Well, I'm 48. Luckily I didn't inherit the balding genes nor have I been muscular. On the other hand, good god I'm tall (6'3") weighing in at 160 with big feet (13 men's). I will never be 20 again so those feminine years are past me. However, there are plenty of lovely ladies (CIS and Trans) 40+.
Try not to dwell on the "what ifs," but instead focus on being the best possible YOU that you can be. Once you get that going on the inside, it will radiate to the outside. Muscle mass will decrease, nothing wrong with quality wigs (you'll shed less which is good). Grow from the inside out and you will rock it.