Review this sentence for pronoun usage‏

This is either the conclusion or first part of a longer sentence. For example:

One wet winter night, just as they got home from a date to celebrate her birthday, the rest of the sentence happpened.

You don't need to mention the rain – one wet winter night already says rain. (Excellent use of the W sound, by the way – what about windy?)

The reason that Grammarly suggests that you review for pronoun usage is because you use two different pronouns in one sentence.  You should make sure that in context with the surrounding sentences, that the reader is sure who these pronouns refer to.