We use -t- only in questions between the verb and the singular pronouns "il" and "elle" when the preceding verb ends in a vowel. This extra -t- has no special meaning. It is added "for the ear" to avoid two vocal sounds in a row, which we perceive as not beautiful. It also allows in a way to better separate verb and pronoun.
--> No extra -t- between verbs and pronouns, because verbs already end in a consonant.
Maman donne-t-elle... ?
--> Extra -t- because the verb does not end in a consonant. In this case, -t- is mandatory. Donne-elle* would be incorrect.
Hope it helped!