I love this woman, who is very outspoken about loving me exactly the way I am! So of course, the obvious course of action is that I need to change myself!
I actually think Nana is correct in that she needs to change, because what (I presume) she's referring to is something distinct from what Luliam loves about her.
Nana needs to build confidence in herself, and to learn to trust in her own ability and to develop more agency over her life. Those aren't things that run counter to that which Luliam loves and appreciates; they are facets of Nana that, once cultivated, will allow those "Loved by Luliam" qualities to fully manifest and shine brightest.
She has to unlearn the self-deprecating behaviors as well, and how to control and minimize those thoughts and mannerisms that only force her away from Luliam and those others who seek to help her. We see it in this very chapter--she thought it better to simply give up on Luliam and let her go with Daichi instead, purely because Nana doesn't trust in herself.
That is something that
will hurt Luliam, and Nana realizes this and seeks to overcome these harmful aspects of her mindset.
Nana is seeking self-improvement, which should always be encouraged and celebrated. Who she is at her core isn't going to be adversely affected, provided she remains aware that she
does have Luliam, and other allies and friends, to lean on when required.
And once she has achieved this, she'll become that much better of a partner to Luliam, and stand on equal ground in a way that only augments them both.