Hello,
There are chances she could get pregnant.
You should know that even non penetration into the vagina and ejaculating on thigh can also get a girl pregnant. As sperms are motile for a few hours after ejaculation, thighs if moist. The sperms can enter the vagina. It's very rare, but there are possibilities. You can try urine pregnancy test to know if she has got pregnant.
Always take precautionary measure of using a condom when having sex. Never go for unprotected sex as apart from pregnancy you can get many STDs. Even if you have unprotected sex, try taking after pill to prevent pregnancy.
Thank you.