@Bass Momma - one of my smaller-statured students, the one who played standing, was constantly struggling with how to set the endpin in order to find the place where both of her arms could reach where they needed to go. If the pin was set too low, she couldn't reach down to the bridge to comfortably get the bow where it needed to be. If she set it higher, she was having to reach way over her head to reach notes with the left hand in the lower positions. I don't know that she ever solved this issue (she is no longer at my school and I haven't seen her for nearly a year) because she was hesitant to experiment with angling the bass either from a standing or seated position.
The other one, a classical bassist studying jazz as a secondary interest, is a force of nature and will not be stopped in any endeavor. She found a way to play seated that allows her access to all registers of the bass. We spent a fair amount of time talking about the mechanics of seated playing, and how the tilt of the torso on the seat combined with an ergonomic angle of the bass can allow the body to be in position to play in all registers. I sent her a video of Ms. Campet after witnessing that brilliant performance with a note about how all of that seated ergonomic theory can translate to the standing posture. She still plays seated, but I'm sure she learned a few things from it, as anyone who actually watches that aspect of the performance would if they were watching it through that lens.
One thing that I advise all students to be aware of is the geometry and mechanism they are working with. With smaller-statured students, I measure their wingspans and advise them to use these resources very judiciously because unlike longer limbed bassists, they have less to waste. For example, the two students above have spans of 62" and 60", respectively, compared to my 74" span. For this reason, teachers need to be aware that what works for them may not necessarily work for their students and vice versa. A good teacher should be aware of this and work with the student with the geometry they actually have to work with in mind.