Hi Charlotte,
No, I don't think that necessarily there is a link between a 45 min nap and the ability to fall asleep independently or sleep through the night. From what I understand a different part of the brain regulates night sleep and day sleep - the key is just that your LO is able to get to sleep at the beginning of the sleep. Many LO's struggle with 45 mins naps that are able to get through the night.
I definitely think that your LO can call out to you during the night at times when she doesn't need food. My DS went through a phase of this too - basically he wanted to check that I was there and that I would come when he called to me. I think he was "testing" me - just checking that even when I wasn't in the room, if he called to me I would come. I responded by quickly going to him each time he called out, to reassure him that I was there and give him a little cuddle if he needed. He has since stopped calling to me during the night becuase I think he is now confident that if he does call to me then I will go to him.
So I think this is proabably a part of your DD's development - she is needing reassurance from you. It is a rough ride but I would keep doing what you are doing, going to her and responding quickly and appropriately. Soon enough she will learn that if she calls you, you will come. Oh, and there is often a 6 month growth spurt so be mindful that she may be needing a night feed or an extra night feed to help her over the bump.
Good luck!