DD aged 5 months, born at 42 weeks and on 55th centile. Has been EBF since birth. She did early on take bottles of expressed milk a few times, then started to reject them.
Fast forward to 5 months and on advice from HV, I thought I would just skip to offering a transition cup for expressed milk (and water once she hits 6m and solids). This got a more positive response. DD understands the cup has food in, she asks for it on sight, pulls it towards her. But she is struggling with the spout! I have tried:
Silicone spout cup (Tommee Tippee) - she loves slurping on this one but the milk level doesn't actually seem to go down!?
Freeflow first cup (also TT) - easier to drip milk into her mouth but she seems to hate the spout and fusses.
What she does accept and like is... me feeding her sips from the cup without the lid on, like a grown up. 
this can get very messy but she seems to enjoy lapping the milk and "helping" hold the cup.
Anyone else experienced this? It means we can feed her expressed milk, but she isn't learning how to drink from a cup for herself. Maybe not a problem at 5 months? Should I persist with the silicone spout and hope she twigs how to suck from it? Is it bad to resort to cup feeding her without the spout just to not waste the milk? Have I just not found the perfect cup yet !?