Can my girlfriend catch my pinworms?

Absolutely: Pinworms shed eggs at your anal area. If these eggs are spread from the anus to the hand or elsewise, and come in contact with the girlfriends oral cavity and are ingested, then she can contract them and the cycle goes on and on. Get treated, use good hygiene (good bathing, good anal care, hand washing and changing and washing bed clothing and personal clothing) and get treated again if recurs.

Depends: Pinworms are spread when the dried eggs end up on someones fingers & they place them on their face/mouth where they enter the digestive tract from above, hatch & begin to live in the colon. If your gf has contact with your bed sheets, she can become contaminated as they are often discharged into your underware or sheets. She will not get them kissing or through sex.