Can you try lying down with her? At around 3 months of age, that's what I started doing when it was her nap time. I would stay until she was fast asleep and then sneak away. That way you get a little break.
Your daughter is still so tiny... She just wants the security of being with mummy. You are her whole world. I know it can be tough, being so needed all the time. But I have never heard someone with an older toddler complain about having cuddled them too much when they were little. yet, I have talke to many mothers who regret not having cuddled them enough while they still had the chance...

You are doing an amazing job. Do whatever feels right to you.Don't let anybody tell you what you should or shouldn't do. You WILL NOT spoil her. But on the other hand, you need to find some balance for your sanity, too. This balance will look different for every mum & baby pair.

Sasa