Prem baby feeding issues

Hi, 

Just wondered if anyone can give me any advice really. 

My daughter was born 14/05/18 at 34+5 weighing 3lb 10oz.Add your post

Her main issue has been feeding.  She was feed with a NG tube for 9 weeks, before she could take bottles.  Currently she is using orthodontic teats which she used when in nicu, she will not drink from any other teat.  She was taking hour to drink 70ml so we added an extra hole which helped, however the consultant said this is dangerous so need to find another way to get her to drink.  She is an awful feeder in general which is also meaning shes not gaining much weight even though on highest calorie milk still on 0.4 percentile and 8lb 5oz at 16 weeks. Any advice at my wits end? Thanks