For your first question, as long as she's gaining steady weight, has enough wet & dirty nappies, I'd say she'd be getting enough into her She'd be getting a good amount at each feed by now

With solids, personally, I waited til my younger 2 could sit, hold the food & feed themselves. I did Baby Led Solids with mine I think for all my girls that was between 5 & 6 months, for DS between 6 & 7 months. I did start my older 2 at 4 months, but I didn't know any different.