This appears to be my week to cast a critical eye over the work of others in my field. This time, I was shown some advice given to a writer, and if you know anything about my attitude toward semicolons and present participial phrases, you will understand why this left me weeping in a dark room with smelling salts. Oh, the humanity!
I'm going to change the example to protect the innocent (and the guilty, but that's just a side effect). Here's the advice, in a nutshell.
Semi-Colons join clauses of equal weight. For example a semi-colon can form a compound sentence when used in place of a conjunction:
She wanted to chop down the dead oak and plant vegetables in that corner of the yard.
She wanted to chop down the dead oak; planting vegetables in that corner of the yard.
Okay, breaking it down. Yes, semicolons can be used to conjoin independent clauses, and when we use them that way, they replace the conjunction. That much is correct. But it's a grammar error to use them "to form compounds" in the way described by these sample sentences. This may have been considered acceptable semicolon use centuries ago, but it has not been the rule in living memory. So, barring certain exceptions involving historical writings, we would never do this today.
Yes, you need to work with an editor to make sure your work is as good as it can be. And it's likely you'll learn new things from your editor. Ditto critique partners, agents, and anyone else who is a member of your team. But you have to know your craft well enough to be able to spot their errors, too.
I was going to break down the sample sentences to explain why these are making me twitchy, but in keeping with the theme of this post, maybe you should do it. There are two glaring problems with the revised sample sentence. Post them in the comments!