It does sound like she is being more efficent. At around 6 months Ella started getting really fussy about feeding and it lasted a month or so and then she was back to normal. She used to normally one take one side a feed and only feed for around 5 mins and I was really worried she wasn't getting enough so I was told by plunket to wait an extra 15-20 after the first side and offer her the other side and 8/10 she would take it.

Jett was doing something similar a few months back.  I would try him with boobie first before solids, and he would strain away from me and arch his back.  I would leave him for a while, then try a bit later, and he usually would take it then.  Sometimes it would end up that I'd feed him his solids first, and he'd happily take boob after.  Even though they say to give solids after b/feed at this age, it's just what your baby wants to do, that you have to listen too.

I also tried not giving Jett so much solids, maybe only 3/4 of what I was giving him, and he was happier to take b/feed.  I think if the solids do fill them up too much, they're not interested in b/feed, so cutting down some of their solids might help.