Foster biting

[chemenger]

I have had my current foster for a few weeks and she's generally lovely. However every day or so she suddenly jumps up when I'm sitting minding my own business and bites, hard. She draws blood and it really hurts. Any idea how to deter her from this. Sometimes I can distract her with a feather toy or a laser pointer but tonight I didn't spot the signs and she got me, see picture. I've had to turn down a potential adopter with a small child because I could not trust her.

hisssing very loudly at her might stop her in her tracks, keep a spray bottle with water in it by you and spray her quickly with cold water, what you need to do is break the cycle of her being able to bite you, and i would get that bite checked out at a doctors, cat bites can be really nasty, also another thing you could do if she is going for the same spot is put something bitter like vinegar on your skin, once again to try to break the cycle, also see if theres a correlation with what shes been doing just before she bites,
also if she has sat near you and been good give her treat like a dreamie,