Answer:

My mother always keeps fresh, cut flowers in the house and often uses baby's breath in the bouquets because it makes the bouquets look fuller.

Explanation:

You should never put a comma before because unless it causes ambiguity.

You can put a comma before and, but only if it separates two independent clauses.

The conjunction and separates these two clauses:

My mother always keeps fresh cut flowers in the house (a complete sentence).

Often uses baby's breath in the bouquets (not a complete sentence).

We don't use a comma here.

The only comma we put is between fresh and cut, since it separates two adjectives.