Hi.
I started solids with my LO at 5.5 months because I just couldn’t hold him off any longer. He was very interested, like your LO, but to the point I couldn't eat anything in front of him because he would scream like I was starving him. I planned to wait until 6 months as per guide lines but one day he just wouldn't stop screaming so I gave him some food and he just loved it.
My LO had a low milk intake it always concerned me but he is a small boy and had always gained weight so I think it was just he needed less than some other LOs. What I found when I started solids was his milk intake increased - yeah sounds crazy - I would give him his milk bottle (always offered more than he would eat) then an hour later some finger food and a bottle/sippy cup of water alongside for thirst. I found he enjoyed the food experience and would eat a lot more than I ever expected, but immediately after the solids he wanted milk again. It wasn't time for his next milk but he really wanted some so I gave it to him. So for a few weeks we had a lot more bottles (like 7 per day instead of 4), which was a big surprise to me.
At this young age they aren't expected to eat a lot of solids and even if your LO takes to solids in a big way like mine did, it doesn't necessarily mean the milk will drop. I would begin the solids either now if you can't hold her off or in a couple of weeks and just monitor her milk intake. Worth remembering that yogurt, cheese count towards their total dairy intake for the day too. An oz of cheese is equivalent to an oz of milk.
I don't know where you are but some countries also recommend vitamin drops from this age.
hope this helps some
