"We didn’t use to get up early" vs. "We never got up early"

Question

My friend asked me the difference between these sentences:

1. We didn’t use to get up early when we were children.

2. We never got up early when we were children

I told her:

• In #1, it means that when we were children, we rarely got up early, we frequently got up quite late. Now, when we are adults, we usually get up early.
• In #2, it means that when we were children, we didn't get up early, even once. Only when we are adults, we get up early.

Did I explain them correctly?

Answer 1

In your explanation of #1

In #1, it means that when we were children, we rarely got up early, we frequently got up quite late. Now, when we are adults, we usually get up early.

"Got up quite late" is additional context which is not implied by your sentence

We didn’t use to get up early when we were children.

but you are correct that it implies there may have been tomes when you did rise early, where as

We never got up early when we were children

states that rising early never happened as you correctly explain in

In #2, it means that when we were children, we didn't get up early, even once.

Whether you rise early as an adult might be assumed, but is not implied by either of your original sentences.