Thanks for the input guys , mom has a good pension (in chinese terms) but not so good based on uk rates , Mom is early 50's and already retired so like you said she would be seen as a drain on the nhs in the future i guess , but i can and will sponser her for ALL costs if necessary.
Three years seems a long time , i thought it two to get perminent resident status .. even so i wonder if in that time mom will be allowed a visitors visa to stay maybe 6 months , then after another 6 months apply again .. im being hopeful i know but with myself and Sissi wanting a family i really dont like the thought of mom being 'stuck' alone and missing out on the kids