Hi N.,
First, I would like to congratulate you on your twin girls...and on you being able to handle them! It must take a lot of work:)
Second, a little about myself...I am a 25 year old mother and wife. My oldest is 4 and my youngest is 7 months. My children are both little girls, but my oldest is a complete tomboy:). My youngest was born with a cleft lip/palate. She had just had her first surgery this past August...we have many more to go through, and it is a hard process(emotionally).
Anywho, about you little ones...Yes, it is fine to start soilds. In fact, you could have started her on rice cereal at 4 months. Do not be scared to try new things with your girls...just use common sense 1st. So far, I give my little one, Rice and Oatmeal Cereal, Apple Sauce, Bananas, Green Beans, Sweet potatoes, Pears, Carrots, Chicken, Bread, Corn Bread, Puff Snacks, and egg. She shows no signs of allergic reaction...and you should never try 2 new things together because if she is allergic to something...you will not know what it is...always wait at least 3-4 days until introducing something new. My little one LOVES to sit in her high chair and eat while I am eating, cleaning the kitchen, and/or making food.
Oh, and I do put my daughters food in her bottle...NOT because I am lazy, only becasue it is easier for her to eat it that way because of her cleft palate. I do feed it to her on a spoon as well, but once she starts getting fustrated and it starts to come out her nose, I stop and put it in her bottle. She eats it up! She loves to grab her food and put it in her mouth...so she does a lot of that with the puffs and breads!
I hope this helps you! Good Luck, A. S.