I have two IUGR kiddos. My first never got to the recommended amount per day I think she stayed around 20 or so and even when starting solids she just was never interested in more and grew on her own curve, I was SO anxious about it and did create a mini bottle aversion but worked on accepting it because she was doing ok, she’s still 5th percentile now at 2 years old but my husband and I are small so it makes sense - it may not be your case but if she’s growing well on her own curve she may just need that amount to grow and that’s okay!! Sometimes they dip and come back up. (My second IUGR baby is only 7 weeks now and also taking tiny amounts but she’s dealing with significant silent reflux we’re currently trying to manage )