What Sisters units do I start with?

Farrah (Dave's wife) wants to start a Sisters army but needs YOUR help. She's brand new to 40k and needs advice for her starting force. What units should she start with? What's a must-have HQ choice? Calling all Sisters players! A sister needs your help.

Music used:
Devastation and Revenge by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song/3644-devastation-and-revenge
License: http:...

Farrah (Dave's wife) wants to start a Sisters army but needs YOUR help. She's brand new to 40k and needs advice for her starting force. What units should she start with? What's a must-have HQ choice? Calling all Sisters players! A sister needs your help.

Music used:
Devastation and Revenge by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song/3644-devastation-and-revenge
License: http://creativecommons.org/licenses/by/4.0/

Rites by Kevin MacLeod
Link: https://incompetech.filmmusic.io/song/4292-rites
License: http://creativecommons.org/licenses/by/4.0/