I think she's just closing her eye because she's relaxing when you pet her.
Frequent squinting can be cause for concern and can be due to eye disease.
I noticed a rabbit that I recently judged was squinting. Upon closer inspection, I noted abrasion to the cornea of both eyes which was causing irritation to the eyes.
I've also noted that rabbits with entropian will squint.
I think her lid is normal. Her eyelashes do not touch her eye. I'll look for some abrasions. I think that you are right, she is just relaxing when I pet her, but is still keeping one eye open!!:thumbup