My sister will be 16 next month & lives with my mother & her boyfriend (who is an alcoholic). My father pays child support but never sees her. Im 23 & married to someone in the military. How can I get guardianship over her to get her out of this environment? And if I can, will my parents have to pay child support?

You would have to go to Family court and petition for guardianship. From there you can escalate it to custody and file for her father's support payments to go to you.