Yes, if she can feed herself she should do so. She'll know to stop if she's feling nauseated or is about to sneeze or cough (which can give you an interesting and messy lesson in fluid dynamics if you do that with a full syringe of food). When I had my first PEG put in, the nurse at the hosptial that showed me how to use it was great. She said "think of it like a bath toy you're playing with and it makes it not seem so horrible". I don't know, maybe that advice seems wierd to other people but it made me much less tense about using the syringes to feed myself when I eventually had to (which wasn't until several weeks later)...