I think she looks perfect for this! I don't know why they call it gothic though. Okay, info time.

She's actually wearing a lolita dress (with no blouse, but I'll let that slide) which leans sweet or old school. I guess it could be considered gothic but it reads really cute... https://twitter.com/NibrocRock/status/1047941440247136260

Some examples of (black) old school lolita! Note the similarities. The third picture is a really great comparison. On the far left is gothic lolita, and the two on the right are old school. It's called that because it's from before a lot of brands and substyles were started

Here are some solid/nonprint sweet lolita dresses next to their black/white colorways. I think they can lean old school or sweet but these just read more sweet to me for some reason. Also, I think the last one is one they might have referenced for the outfit!

I had to clear up the misconception cause a lot of people think black=gothic but it doesn't! Here are some printed sweet lolita dresses in black; they're not very gothic looking

As for some dresses/outfits I would consider more goth..

I hope this thread is helpful!