Reibun
？

There are abilities that improve quickly and ones that improve slowly, right?

Literal

Ability [at-には] quickly improve ones [and-と] slowly improve ones [subject-が] exist [agreement-よね]?

早く上達するもの ('things that improve quickly') and ゆっくり上達するもの ('things that improve slowly') are parallel relative clauses modifying もの ('things/ones'). ありますよね seeks agreement with the polite よね tag. A simple but pedagogically useful observation about learning — the kind of framing question a teacher might ask.