Finding out the right tense

This is a good question, Alexandra,

This is a story in the past and the clue was in sentences at the beginning -

When my daughter was little 

The verb 'être' (when in the past) is almost always in the  imparfait as it is the quintessential verb of state.

we used to go to the swimming pool 

again the imparfait as something you 'used to do', suggesting a repeated action in the past.

The ensuing verbs will be in the imparfait as well as they are describing other repeated actions in the past 

Here is a lesson on the imparfait to refresh your memory if need be -

Expressing past habits or repeated actions with the imperfect tense in French (L'Imparfait)

Bonne Continuation !