I recently built an all rigid steel 650b with XX1 crank, Stans Crest Ztr, X9 rd, carbon seat post, carbon bars. weight is 23 lbs

My new project is Chinese carbon frame. I'm building this for my wife.

Any suggestions for components? I want to keep weight to around 20 lbs.

Should i go XX1 again for simplicity for her? What wheels and tires?

What brakes? What fork?

I have a mid-grade budget - say $2000. I already have the frame.