It is about client education. As you gain experience you will start to understand skin better and be able to assess problems that you don’t know how to deal with at this stage of your learning journey.
In the U.K. we generally don’t look after our skin well. In other cultures it’s quite normal to invest time, effort and money on skincare. When I was in college I learned this quite early on - we had a Japanese student who was quite embarrassed one day when she was modelling for a treatment, apologising for her “disgusting” skin. There was absolutely nothing wrong with her skin - it was the same as everyone else’s, her expectation seemed completely unrealistic. However the next day she came into college and showed us. She had spent the previous evening “catching up” with her normal skincare routine and the result was astonishing. What we thought of as genetically lovely skin was in fact a cultural expectation to spend time and effort taking care of skin and maintaining a very “high” standard.
The ingrowing hairs you describe are caused by the combination of her skincare not being good enough to overcome the friction and dehydration issues caused by her clothing - her skin needs to be much softer to allow the hairs to penetrate the skin surface.
Modern clothing and fashions have dried out our skin and that feels normal, in fact skin should feel slightly waxy like a nectarine, rather than like a washed potato. Tight clothing like leggings, long socks and tights can restrict circulation to the outer layers of the skin. Being bare legged can be dehydrating for skin. Technical clothing can also wick moisture away from skin. There’s a reason why long skirts are traditional female clothing!
So your sister needs to up her game. In the nicest possible way, it sounds like her skin lacks hydration. This may be because she isn’t drinking enough water and instead drinks flavoured, sweetened, caffeinated or alcoholic drinks to quench her thirst. So suggest that she monitors her water intake and adds 250 ml to her daily consumption twice a day, maybe as a routine morning and early evening discipline and see how her skin changes. (Depending in where you live it might be an idea to filter the water as there are quite a few dissolved metals and other particles in water that can be hard on your organs if you suddenly up your intake of water, I decided to increase my water intake a few years ago and ended up with puffy knees because I didn’t filter the water, so now I buy spring water).
Does your sister smoke or vape? Nicotine is a killer for skin, there’s a reason why it causes cancer. Anyone exposed to nicotine and inhaled pollution (busy roads, woodsmoke from stoves, industrial wastes, vaping or smoke from anything burning including kitchen grilling) needs additional vitamins to help your body compensate - a good quality multivitamin and mineral supplement is one option. She could try a month’s course and see if it makes a difference.
Skin also suffers from a lack of heart healthy fats and oils. In the U.K. the traditional diet is very high in fish. We are an island nation with lots of rivers and fish used to be a very important food in our diets, other nations have different sources of essential fatty acids - animal skin-on dishes, shellfish, nuts, seeds, yellow and orange fruits. If you’re not eating like your wealthy ancestors (and who does?) try a fish oil supplement, about 5ml a day. Fish oil is not the same thing as cod liver oil, cod is not an oily fish and the liver is a waste organ - cod live quite a long time and pollution accumulates in their livers so supplements from cod liver are not the gold standard, Fish oil is made from the blubber of small, short-lived oily fish swimming in unpolluted waters.
Encourage your sister to take up skin brushing - use a bristle brush and brush on dry skin, before a shower, in long strokes towards the heart. This is a lymph draining activity, not a scouring activity, you are intentionally stimulating the circulation and encouraging lymph to move in the direction of the lymph nodes. A 2 minute daily cold shower is a good alternative, but not for everyone, I’m ethnically from a warm to hot climate so my skin needs to sweat to stimulate the circulation, being cold just shuts my circulation right down, so it is about understanding what works for each person.
I have found that Japanese wash cloths (made of a kind of knitted plastic) are a skin game changer. They do need replacing once a year and you may wish to use something non plastic, but the principle pf a textured cloth to lightly scrub your skin is something to bear in mind. My skin has a very high skin cell turnover so I feel quite grubby at the end of the day and my legs get very dry in the U.K. - it’s usual for my skin to look scaled during the winter months. Discovering Japanese washing rituals gave me the best skin of my life!
Finally Moisturising, it’s the final, but essential step. Skin needs to be hydrated from the inside with plenty of water and oil to help hold the moisture in, so that’s about diet. The skin circulation and lymph need to be in tip top shape, so that’s where good washing rituals help. And a topically applied moisturiser helps to protect the skin from excessive transpiration. There’s a perfect moisturiser for everyone so it is about experimenting. Some people need lots of a light lotion - aloe Vera for example, others need a richer cocoa butter lotions, sone need something richer like a Shea nut butter. Some skins love oil - baby oil is basically cling film so it seals in moisturise it doesn’t add any, nut and seed oils all have different properties, some leave your skin very greasy, others are very light and make your skin feel “just right”. If your sister isn’t getting great results from her daily applied all over body moisturiser she needs to buy something different. If she hasn’t got on with a light aloe Vera lotion, she could try an oat based product, or cocoa butter. Don’t switch brands and buy something with similar ingredients to the previous disappointing product. Try a different hero ingredient and see how she gets on.
It’s worth bearing in mind that clients are lazy and they lie. No-one is going to admit to not taking the advice you gave them. By asking what product they are using, and suggesting something else for next time, and commenting on their skin “better than last time what did you do?” “Really dry, have you been stressed recently” you are coaching and supporting your client to relearn her self care rituals. My clients “hear me” when they are in the bathroom, reminding them to apply their moisturiser, and they know that I will notice and congratulate their efforts. It’s the relationship and connection that you forge with your clients that get them to return to you and recommend you to their friends. It’s also very rewarding to be appreciated. A win win all round.