Yes, perfect!! Only the punctuation is a little wrong.
"Thank you, Julie. That helps me; however, I wonder if I can use it naturally or not" is better.
In English, if you use a comma (,) to connect two complete sentences, you also need a coordinating conjunction (for, and, nor, but, or, yet, so). If you tie them together without a coordinating conjunction, we use a semicolon (;). So "however" can come either at the beginning of a new sentence ("That helps me. However; I wonder...") or after a semicolon. And it has a comma after it!
I hope that wasn't confusing. It's not a very important detail. Other than that, it was perfect. :-)