Can my mother wrtie will...?

Property 4 generation removed without any partition etc comes into the category of ancestral property now. All " co parceners" now have claim to it, per specific situations.

So your mother can't do as she wishes. Take advice of a property matters lawyer to avoid problems in the future.

DISCLAIMER : General information and advice provided is without any warranties as to suitability for any use, correctness and application to any specific case. Please always take proper legal counsel . However, if it helped anyone even a little a " thanks" would be appreciated and would encourage me to keep on making efforts :-) . I am also always open to corrections and further learnings from more experienced Seniors here.