Is this a sentence fragment your brother Chantelle and I all escaped from the trouble?

Yes, that is a sentence fragment. It is missing a subject.

Here's how you can fix it:

* "My brother Chantelle and I all escaped from the trouble." This adds the subject "we" (implied by "my brother Chantelle and I").

* "My brother, Chantelle, and I all escaped from the trouble." This clarifies the sentence structure by separating the names with commas.