I dont know where you live but mostly in the US it is not reccomemded that babies under 6 months start solid food, but if your Doctor said to start it ...if she wont eat the cereal I would suggest you give her more formula, until she is a little older, then you will be able to introduce other foods, i guess 3-4 bitesof cereal is better than none , mixed with formula. Others here may have more ideas . Good Luck
You can definitely take your time getting her to eat. I too was told to introduce baby cereal between 4-5 months, but I waited closer to 5 before I introduced it regularly. A few bites is fine for now...remember, it's her first solid food EVER! Until 6 months you don't really need her to get any nutrition from solid foods, and she won't be capable of eating enough of it to fill herself up, so right now all you're doing is practicing with her. I was allowed at 5 months to introduce fruit/veggie purees, and I started first with a little bit of peach puree mixed in her rice cereal at 5 1/2 months....she ate a few bites of that. Your baby will eat more as she gets used to "solid" food and she will be just fine...so don't worry about it yet, and no I wouldn't introduce any of the baby foods aside from pure rice cereal until she's about 5 or 6 months. Stick with a few bites of rice cereal once or twice a day for a month or so.
She will do it when shes ready. The best thing in infants and toddlers is to let them go at their own pace and dont force it on them and dont get frustrated.
My son is now 8 months. I was told to introduce cereal at 4 months and if he didn't like it to wait until 5-6 months. My son liked it the first time I gave it to him. If your child is not taking it very well, I wouldn't rush. Give it another month. When your child is ready for stage 1 fruits try mixing the plain rice ceral with a little juice (apple or grape). Sometimes I mix with apple sauce or any other stage 1 fruit. My son didn't like the rice ceral when I would make it watery, he only likes it when I make it a little thick like mashed potatoes.