I hadn't thought of the Lady of the Lake connection...Nice!
It looked like the mermaid/siren/lady of the lake changed her face to look like Snow's so maybe the queen put her up to it in order to seduce the Prince and stop him from saving Snow. We know the Prince is looking for her but she took the magic potion so she doesn't even remember him. We also know that at some point Snow has to end up in that glass coffin because they already showed that part several episodes back. Blahhhhh I don't think they'll skip that far ahead though.
For some reason I didn't immediately think of The Little Mermaid. I'm sure they do it at some point though. They are probably saving some of the more popular fairytales for later seasons.