Welcome Yota
Clone mothers do not need very much light at all.
I would say 1 26w cfl would work.
I use 15w 21" pruple grow fluro's for my mother and clones.

I guess it depends on how fast you want her to grow.
At the rate I am going I will be able to continue taking 4 clones every 2-3 weeks off of this same mom with this little bit of light.

Happy growing