i recently listened to "cancer and mms" a radio interview with jim humble
--since you are dealing with cancer maybe you could give it a listen if you havent already.
the link is below.
a couple things he talked about was dosing more freqently with cancer (as i see your mom is doing) and he also mentioned that some dont see cancer markers going down until 3 or 4 months, but not to stop taking mms. hope you can listen.