Question

there is no mother but loves child (affirmative) ​

Answer 1

Explanation:

there is mother who loves child

Answer 2

Explanation:

Though 'but' is usually a conjunction, 'but' in this sentence is followed by a verb 'love(s)' and works as a pronoun. This can be regarded as a pronoun.

You can replace this 'but' with a relative pronoun and negative word.

=  There is no mother who does not love her child.