@NBRI I'd say that it's cool to mention that somebody's work inspired you to create an alt of your own - that kind of thing is motivating to hear, and hey, it's not like Izzabelle's alts aren't works of art that set the entire Terrarian fanbase drooling. I was stalking these even before I had an account, and I'm still weeping over the Necropolis, Glade, and Vermin Horde I'll likely never have. (Also, Quetzalcoatl. I
love that boss design.) Even posting a sprite you did and saying it was inspired by one of her alternates is probably good.
But you should make sure to talk more about the thread's topic than your own stuff (that's for a different topic), and it's a bit :/ to ask someone to help you with your projects out of the blue. Izzabelle has various alts either WIP or on a to-do list, something outlined in detail on this very thread. So while I can't speak for her, it's not that likely she has room for more projects. She hasn't been very active lately anyway.
Typically, you should only ask for help if you either know a person already and have a decent rapport with them, or if they showed interest in your idea first (even if they just came to your thread and left feedback.) Soliciting people on their projects for your projects isn't very productive and is generally frowned upon.