My heart goes out to you Mama, as I remember that lousy panicky feeling that causes horrible thoughts like: "Maybe my baby isn't thriving? Maybe it's my fault? Maybe she isn't getting enough protein? Maybe I need to start force-feeding her?" ARGH!!! (For me, I remember really obsessing over protein, as if my baby was a pro football player or something.) Those thoughts will drive you nuts. And I'm sorry but the stupid doctors and their stupid percentiles ... will also drive you nuts. I must warn you that I've been on a rampage against doctors lately, but I really don't hate them, In fact I think it is important to listen to them and take in what they advise you. You just need to take certain things they say with a grain of salt. Like those percentiles. I recently posted another answer about this if you care to hear more of my rampage :)
1) Your little baby is fine. They are all so different. I can promise you that in due time, her weight-height will even out at her own pace. As long as she is eating/ drinking something, and she is not losing weight, she'll be fine. Even if she turns out to be small, that is normal for some people, thus a world of very different looking people. Maybe she'll be long and lean, and if so will always wind up in a lower weight percentile.
2) If your instincts are telling you she is fine, happy, healthy, and vital, then trust these and do not let your fears take over. It's hard because your fears are blown out of proportion because of your protective nature (this is also normal). You just need to keep the fear in check. And steer clear of future- hockey-moms who make you feel worse by rubbing it in your face (They mean well, they're just proud that they have such chubby cute kids.)
I went through a month or two when I was having breastfeeding/ pumping issues when my son was around 3 or 4 months. Looking back at pictures, he did look a little thin. But he was slowly gaining, just not fast enough until we straightened out the issues and he plumped right up. Still, he's never been chubby but he's tall. I'm 5'10" with a fast metabolism, so no surprise.
3)Do you know that in some countries, babies are exclusively breastfed until around 1 year? So don't feel bad if you need to continue that a little longer than you planned. That is all she needs until 1, any foods you start her on now are mainly to get her used to the taste and texture as well as the muscular movements needed to chew and swallow. But that can wait. Solids prior to 1 are not so much for the calories and nutrients as long as she's still getting plenty of breastmilk or formula. I didn't even start my son on solids until around 8 months, and I didn't push them the way many people do. Today my son is incredibly healthy.
4) I don't recommend dairy before one year especially if she's shown signs of intolerance. It could actually prolong an allergy whereas if she isn't exposed to dairy now she's likely to grow out of it on her own. At least that is what our pediatric allergist said. (See, I do listen to them sometimes!) ps. My son had this allergy too as an infant, then one day around 10 months my husband accidentally gave him some food with butter, and he was okay with it. Yet was still having a reaction to tastes of yogurt and other things. I asked the doctor and he said butter was mostly fat, and was probably ok to give him if he didn't seem to have trouble with it.
5) Here I go again listening to doctors advice, but I was told by one pediatrician not to give babies meat until after one year. He said the "pulverized" meats in some baby foods are ok though. Another pediatrician at this practice didn't have a problem with infants eating meat. I just wanted to point out that there are many different opinions and not all docs agree, obviously not all moms. My son hated the texture of any meat until he was around 14 months and since he couldn't have dairy until around 18 months, thus began my protein obsession. I continued to buy those jars of baby food with chicken or beef (organic) until he was at least 14 months!
6) sometimes you have to take cues from your baby. It sounds to me like she just plain isn't ready for alot of solid foods. Like other women have suggested, keep trying but don't stress about it. She may have sensory issues or be one of those kids who is very sensitive to texture, but now is too early to really say. I think you are doing the right thing with mixing a little fruit puree into her cereal or even try blending sweeter veggies in, a little at a time. I agree with the mom who suggested using a blender and mixing your purees into a very smooth blend. And also the concept of introducing a flavor one spoonful at a time. Like, my son never was crazy about avacado but i really wanted him to eat it. I found that I could mix a spoonful of mashed avacado into butternut puree and he'd eat it. If I went for two spoonfulls, he'd get wise and spit it out.
I wish you and your daughter the best of luck!