She is too young at eight weeks, and is getting all the nutrition she needs from formula. The American Academy of Pediatrics suggests starting no earlier than four months of age. Some babies are not ready until they are older.
Before four months of age, babies natural reflex is to push the tongue against whatever is put in her mouth. This is necessary to allow infants to nurse or drink from a bottle.
Do not add cereal to a regular bottle as this could cause your baby to choke. Even if there is little cereal, she will have to suck harder than usual to suck the cereal through the nipple. Some mom's suggest cutting the tip of the nipple, but that causes the nipple to slowly disintegrate. If a baby is ready to eat solid foods, s/he will be able to eat it from a spoon.
SOME Signs your baby is ready for solids:
* She holds her head steady and sits with support.
* She reaches for and shows interest in food.
* She opens her mouth when she sees food.
* She no longer thrusts her tongue out during feeding, so she's able to keep food in her mouth and swallow it.
* She turns her head away when she's full.
Please take a few minutes to check out the sites below as they offer a ton of useful information regarding feeding your baby solids.
American Academy of Pediatrics:
http://www.aap.org/publiced/BR_Solids.htm
About.com article on solid foods:
http://pediatrics.about.com/od/infantparentingtips/a/04_s...
Under my pediatrician's guidance, I was told to start my son on rice cereal at 3 months. This is because he was drinking over 60 ounces of formula a day (and spit NONE up) and was still acting hungry. Once we started the cereal once a day, he did better. However, this was suggested by his pediatrician after I kept a log of how often he ate (every 1.5 - 2 hours) and how much he ate per feeding (usually 6-8 oz, though sometimes he drank as much as 10oz in a single feeding).
If you are concerned that your baby isnt eating enough, keep a log for a week of how many ounces she's eating at each feeding - and make sure to notate if she's spitting up and how much. Then make an appointment with your ped and take her in, along with the log and see if your doctor has any other suggestions.