Defintely try to get full feeds and work on extending the naps, if you can. One will work on the other - if she's eating more each feed, she'll go longer until the next one, and if you can improve the naps, she'll wake up hungrier! Do breast compression, try both sides per feed, and check the nap board for suggestions on extending naps (swaddling, white noise, limit activity time...) HTH!