Try alcohol wipes. You may have some in your first aid box. I was taught by a tutor who used them for taking off lashes.
Oil (light mineral oil) may loosen a dollop of lash glue. As Alanya has said, you need to separate the hairs so that you have smaller bits of glue to remove rather than one big tangle.
I once had to remove hair removing wax that had been dropped onto my daughter's long, fine, naturally curly hair. You have to be careful not to put too much stress on the hair at the root, otherwise the hair will pull out of her scalp and she'll have a bald patch, followed by a sticky up regrowing tuft for months.
Good luck. Put some music on. Offer a drink and biscuit and stand/sit where your client can't see your face so she can't see you stressing. Hugs. Xx
