Thumb nail - what is this?

[Prillydarby14]

A client came to me today with a thumb nail looking like this (see attached image).
All her other nails were fine. She doesn't remember any obvious nail trauma.
To me it looks like the nail is lifting from the plate so could be Onycholysis but could it possibly be fungal?
I suggested she get it looked at by her GP if she was concerned.

 

[Prillydarby14]

 

[Trinity]

No fungus, I'd say onycholisis from incorrect pinching or tips too small. It may also be repetitive trauma, opening a phone case, button, something she does with her thumb all the time.