A kind answer can include a limit without losing the kindness that began it.

Warmth and refusal get treated as opposites, so people either give more than they have or go cold in order to say no. Neither is necessary. A limit stated plainly, in the same voice you used for the welcome, reads as honesty rather than rejection, and it usually protects the relationship better than a yes you will quietly resent.

Say the next no in a warm voice without softening it into a maybe. Offer what you actually can, then stop. Keeping both halves in one sentence helps the care and the boundary arrive together.