New girls need a solid agent and they need to build a good reputation. Its hard to get work from folks you've never met, do some time with a good agent or two before you try to book yourself.

Network to meet some directors and talent both online and irl. Show up on time, remember your IDs and shit, have some outfits with you. Watch a few scenes from the site on your phone and see what they are looking for. You can do this during makeup.

I think the answer to almost every question you ask is yes. Yes, she should diversify, yes it's a slow season, but AVN is right around the corner and fresh faces are needed.

If she doesn't want to get shot-out quickly she may want to hold back anal and IR and re-introduce herself over and over with each upgrade.(or downgrade depending on your view). For that to work, of course, she has to be hot enough for there to be interest in her new scenes.