There are some methods in this post that cover how to scrape from Fansly. You can view the post without an account but you'll need one to access provided links. Depending on your level of comfort, there are tools that rely on Python but I personally recommend this one for ease since it's a simple installable .exe for PC.
Could just ask her for a Dropbox lol. But I would try a good bit of things, downloader extensions, screen cap, etc. there may be a link embedded somewhere you can download.
yt-dlp supports various sites and authentication options (may have to take over from webbrowser). I don't see an explicit extractor in the source, but it may work anyway. It's what I'd try first.
1DM and 1DM+ it's a download manager available on Play Store, I used it to rip some content from OnlyFans a while ago, I believe it should work with Fansly too but you will have to try. Good luck.