The sentence has two clauses: "Please watch the babies" and "while Mother takes a nap". (You didn't underline a clause so I'm going to explain both of them).
First Clause: "Please watch the babies"
This is an independent clause. You can identify independent clauses when you read it and it has a full idea already. It can stand without another clause to back it up.
Second Clause: "while Mother takes a nap"
This is a subordinate clause. Subordinate clauses usually start with a conjunction. You'll see that the given clause starts with "while", which is a conjunction.
1. Static character
2. Plot
3. Theme
4. Characterization
5. Setting
6. Symbolism
7. Dynamic Character
8. Narrator
9. Imagery
10. Protagonist<span />
She told him she was pregnant
Yes! Contrary to popular belief, “they” has actually been used as a singular subject in language for a very long time.
