Being female does limit options a bit, the only really effective agents at increasing muscle mass are androgenic anabolic steriods , testosterone and similar, but use and doses in females need to be done much more carefully to avoid or minimise adverse effects.
Secretagogues and hgh probably make a small difference to body composition , few percent at most unless using unsafe doses.
Optimising exercise and diet are the main requirement, gaining muscle in a calorie deficit is nearly impossible.
Ostarine at low doses might be worth considering , was studied in humans with semaglutide at 3mg and more or less abolished muscle loss with weight loss, and is thought to be safe at least in lower doses in women, as a SARM with low androgenic effects. Only available in 25mg pills from very few sites, so getting 3mg doses is going to require some mucking around crushing pills and measuring with accurate scales, but is at least actually proven in trials in humans to reduce muscle loss with weight loss with GLP drugs, and is quite low risk for toxicity at those doses. As far as I know it is still being actively researched as an add on to GLP drugs, which is a good safety signal.