how do you gain muscle and make her look more beautiful and learn to do makeup better lol
Work out (can use the gym in business district or the boxing Gym at the wharf) you need to be a little careful as some of the exercises can have other effects, like using the ball can make you get a bigger bum, or lifting weights can make your breast smaller. Yoga can make you super flexible if you do it enough.
In the Mall on the second floor is a beauty salon, they sell home use creams, if you apply this daily, you gradually improve your looks. Laser hair removal is also a solid move (when you have the cash) as it gets rid of having to shave.
At the community centre (off the business district) you can attend a course once a week where they teach you the makeup skill, other than that, it is like the old joke, "how do you get to Carnegie Hall?" "Practice, Practice, Practice". It isn't a quick process (unless you cheat), even though you make a shit job of your makeup at first, if you stick with it, you will get better.
You can also make your eyes look bigger and more attractive if you sign up for medical test in the down town district, although I think you need a bank account before you can do it. Be careful with the medical trials, some of them have harsh side effects, although the eye one is not one of them.