Hi and welcome to the forum.
I've made dumplings with butter rather than suet. They're prone to breaking up and seem to take longer to cook than the version with suet, so if you're going to try this method I suggest you make the dumplings smaller than normal.
Here's a link to how to make dumplings without suet:
and a link to a picture of the dumplings popped into a soup:
If you're not confident of success, I suggest you cook the dumplings separately from your stew because if the dumplings break up too much they could spoil the taste and texture of your stew. You can cook them in a separate pan by simmering them in vegetable stock or a stock made with Marmite. Good luck! Please let us know how you get on.