Am I starting bad habits?

Every afternoon my 4 month old daughter feeds until she falls asleep. She normally eats quite a bit. About 20-30 minutes after she falls asleep she starts crying in her sleep and rooting around until she eventually wakes up. She then nurses for about 5-10 minutes and falls right back to sleep for another 30 to 90 minutes. Do you think she's still hungry or unable to self soothe? She won't take a pacifier and chokes when she sucks on her fingers, so I think she just likes the comfort of moms . but am I creating bad habits by letting her nurse to soothe herself back to sleep instead of letting her try to fall back asleep on her own?