This is nowhere near enough to be conclusive though it is a fun possibility. Given how quickly The Owl House is being abandoned though there's not much point in confirming that link.

I don't see it as "canon confirmed" because it could just be Easter eggs, but Stan himself describes Marilyn as having pale skin and an abnormally sharp tooth and met in Las Vegas."

Dana also mentioned that Eda was in Vegas.

You can also see Eda in Gravity Falls: Lost Legends

But this is all not a new thing and the series creators have not said anything clear about it so even though it is obviously Eda - it is not a canon fact.

It's kind of like the Minecraft Story mode Theory that Soren's an old builder. It's never canonically confirmed that he's an old builder but all evidence points towards it, like the thing with Eda being Stan's ex wife

For me she is my ex-wife with everything i'm seeing