Wow this was steamy lmao
But I think this should reaffirm Xiya that Rachel actually genuinely loves her and sees her more than just a mana battery. I mean she has respected Xiya's boundaries up to this point, even going as far as to bite herself so she didnt attack a sick Xiya. And now she's offering to stop because of the strain it puts on Xiya's body. Those aren't the actions of someone who only cares about what she gets out of it. Their relationship is trending in the right direction. Rachel just needs to be gentle and Xiya needs to communicate like she did here.
Thanks for the translation!