She is taking plenty of milk, the minimum the need from 6 months with solids is 20oz, most babies seem to be taking between 24 and 32oz at this age.
You can increase the amount of solids she is having by following her cues, if she will take a bit more than you currently offer you can carry on until she tells you she has had enough. If you continue to offer milk feeds and then solids about an hour after she will still take her milk. Try her with lunch and see how she does, dropping a few oz of milk won't be too much of a problem as she is taking plenty, just keep an eye on her intake and drop the solids back a bit if she does start refusing milk! You can start offering her finger foods too if you aren't already.
Laura