The little orphan girl kept her mother’s necklace as a keepsake of her rememberence.

Is this the correct usage of the word 'keepsake'?

Yes. That's a good use of "keepsake."

However, please omit the last three words.

yea i was thinking the same thing. thanks

Yes, the usage of the word "keepsake" in the given sentence is correct. A keepsake is an object that is kept to remember a person, place, or event. In this case, the little orphan girl kept her mother's necklace as a keepsake to remember her mother.