How do I respond to this?

Truthfully.

I would tell her to not look away from what she already has,she will most likely lose it.

Gratitude is much fulfilling than wishes

Don't assume she is being hurtful. She might be honest, and if you are not together with her she might just have given you a hint she wants you to make her happy. But at least she cares about her niece which is wonderful. Always focus on positive things and mention those.
If you really like her a lot, then why not say, "what about me, I want to make you happy?

A cat give her a cat

Him?

You've just been talking to her for a few days. It could just be she has no expectations of you. But it's also a really odd thing to say. Expect future drama.

Sounds like she is a very kind person. Can you tell her that you are impressed that she is so kind and want to make her niece happy?

You just got friendzoned or shes flirting. Dont ask me idk.

Don't take her seriously anymore. She's gonna break your heart

I probably wouldn’t

I'm confused