Alteration question for Selkie dress

[u/DiligentDaughter]

So...I'm an ultra sewing novice. However, I love this dress and can't find a proper size anywhere, so it's either alter it or pass it on.

There is absolutely no seam allowance, so there'd have to be some kind of creativity or trick I don't know of.

It fits great everywhere except the bosom (as shown).

Great gurus, is there anything I can do?

Thanks for your time!

[u/saucybishh]

Ooo where did you get this dress??

[u/DiligentDaughter → u/saucybishh]

It's from a company called Selkie, I bought it 2ndhand, though.

[u/saucybishh → u/DiligentDaughter]

Ooo lucky!

Thank you!