With yoga, not really. Exercise (running, calisthenics and/or using weights) will increase muscle in the thighs and glutes and slim the waist, but there is only so much that can be done with the genetics we have.
To put on weight, you can go into a trance and affirm that your body is putting on weight in healthy ways for you. Inhale white-gold energy, make the affirmation on the exhale. Visualize yourself with the curves you want, but know that this will only help so far, it won't completely change the structure of your body.
Also, some men prefer your body type. Don't think that you have to change your body entirely to be attractive, there is no one ideal body type. If you want to appear more feminine, then perhaps add feminine accessories to your outfit, wear clothes that are pretty and flatter your figure (as opposed to whatever is trendy), and so on.
And feel good about yourself! It is always attractive when someone is comfortable with who they are
