What's the most comfortable ND the best brands ND the most in type of panties for Twin girls ages 11 almost 12 yrs old.....are gstrings/thongs/cheeky boyshorts /cotton bikini or nothin at all?

What are all the different types of panties for Twin preteen girls that are almost 12 ND are very beautiful with a very athletic builds and they aren't tall
But petite they have naturally curvey hips from there mom as they both also inherited there mom's very firm Apple hbottoms (shape of their bums not trying to sound like a perv or anything just being honest so I can get the best answers) their grandma wouldn't allow them to wear any brand/type of  yoga pants as well as no leggings either only long skirts and dresses but not no more my girls can wear whatever they want no matter how much it shows off there gorgeous young bodies/features well the only features they have at the moment is their bums/hips ND well the most important feature on a girls body their vaginas.     They still yet to develop any boobs yet so when that day comes I'm buying a gun for each one of my daughters ND any boy who hurts then or wants to date them they gotta have a sit down with me an my gun.  ..sorry for the long discussion bout my problem bout being a first time daddy to twin preteen girls ND not knowing what to buy them like panty and bra wise ND when they begin their periods I'm not looking forward to that lol take care
New pround surprise father of two gorgeous tween girls