Onset of puberty related issues.

Hello Doc, my daughter is turning 11 years in Dec. She has started developing pubic hairs. Her underarms hairs are quite visible and it creates irritation to her. My queries are - 1) what is the right age to remove underarms hairs and by what means. If we do shaving then next time thick hair growth will be there. For waxing, her skin would be too soft to handle. Hair removing cream can blacken the underarms. Please suggest if any medicated creams are their for girls of this age. 2) Similar question is for geniatal area hair also. 3) What is the right age to start wearing bra. Although she is slim but she has started developing breasts. 4) Tentatively when we can expect her periods to get started? She is too young to handle this. Not sure if we can delay by any means..