RE: Starting solid foods at 4 months?
If you decide to introduce Leela to solids, don't do it in the hopes that it will help her gain weight. It is actually likely to do the opposite. Solids have far fewer calories per ounce than breastmilk or formula. So any solid feedings that she adds that replace either of those is actually going to be decreasing her total calorie intake.
If you are petite, you can expect that Leela will likely be the same. If your ped was concerned about her weight, she would probably recommend more liquids, not solids.
And please don't trust that Gerber worksheet. Their goal is to get you using their food early and often! You're better off following Leela's lead.
I'm a huge fan of Ellyn Satter's book. If you wanted to borrow my copy, I'd be happy to loan it to you.
HTH,
Beth, mom to older DD (8/01) and younger DD (10/06) and always missing Leah (4/22 - 5/1/05)