Reformat the hard drive which will permanently remove Wife 1.0, Mother_in_law 1.0 and brother_in_law 1.0.
Reinstall with girlfriend 3.0 and run OS in safe mode, ensuring any resources overload can be replaced with a fresh girlfriend 4.0, 5.0, etc.
Place girlfriend 3.0 in a TEMP folder, and create hidden/encrypted folders for girlfriend 4.0, girlfriend 5.0 so girlfriend 3.0 is not aware of any other resources being used.
While running girlfriend 3.0, ensure to use Latex covered static guard to minimize the accidental creation of processes child 1.0, 2.0, etc. which can use more resources than any wife 1.0 or girlfriend 3.0.