You can provide her a lot of opportunities to sleep but can't actually MAKE her sleep (as much as you'd love to
). I think that by getting into her room to check her, that's actually making her expect it so, as long as she's not crying or distressed take that time as quiet time for her being in her room and not needing more intervention than that, if she's tired enough she'll eventually go to sleep.
Another reason is that she might be more tired in daycare for all the activities she does there as oposed to home. Try (as much as you can, I understand that having another lo to take her makes it harder) to have her occupied in physical activities on days she's at home. She can help you with house chores and get more tired that way. Try also putting her down a bit later on those days to see if that does the trick.
HTH!