Staying for extended period and travelling back exactly after 6 months

[Bhargav09]

Scenario 1
my Mom is here in USA for 6 months on B2 VISA, need opinion on what is the best approach here, if we apply for extension now and get in approved for additional 6 months and she continues to stay with us for 12 months, later leaves back to home country and stay there for 6 months, can she come back after to US after 6 months of stay in home country, if so will she get permit for 6 months on her next visit ? ( duration in home country is 6 months and duration in USA is 12 months prior) please let me know

Scenario 2

if my Mom leaves US after her first 6 months of stay and if she comes back in 3 months will she get entry for 6 months again ?

Please assist really appreciate your help in this matter…

[visa_2014]

Legally, it should be fine if she has spent more than 180 in the home country and then come back again otherwise she might get scrutinized at port of entry.