I'm trying to practice entering Sheila's area and my game crashes seemingly depending on how I enter the portal. Does this happen to anyone else, and if so, does anyone know why or how it happens?

If you try to enter the portal too high, the game will crash. Entering it from lower should fix that problem. The loading zone bleeds down pretty far, so as long as you are down far enough, you will be fine.

There is an alternative you could learn which would avoid any crashes (and is faster), found relatively recently, here's a timestamp of a video with it:

The jump around the house to go up the roof is a bit tricky (you gotta use the peak of the door frame to help you) but I didn't find it harder than the original method. Hope it helps!

Thanks, I'm gonna try that.