Dought & clear, - (Abandoning or Neglecting Salaat) ,- Should she do Hajj and give charity onbehalf of her mother who did not pray?.

Is it permissible for a daughter to do Hajj and give charity on behalf
of her deceased mother, knowing that the mother did not pray when she
was alive?.
Praise be to Allaah.
The one who does not pray because he denies that it is obligatory is a
kaafir according to scholarly consensus. The one who does not pray out
of negligence and laziness is a kaafir according to the more correct
of the two scholarly opinions, because the Prophet(peace and blessings
of Allaah be upon him) said: "The covenant that stands between us and
them is prayer; whoever gives it up is a kaafir." And there is other
evidence to that effect from the Qur'aan and Sunnah. Based on that, it
is not permissible to do Hajj or give charity on behalf of someone who
has died and did not pray, just as it is not permissible to do Hajj
and give charity on behalf of any other kaafir.
And Allaah is the Source of strength. May Allaah send blessings and
peace upon our Prophet Muhammad and his family and companions. End
quote.
Standing Committee for Academic Research and Issuing Fatwas
Shaykh 'Abd al-'Azeez ibn Baaz, Shaykh 'Abd al-Razzaaq 'Afeefi, Shaykh
'Abd-Allaah ibn Qa'ood.
Fataawa al-Lajnah al-Daa'imah li'l-Buhooth al-'Ilmiyyah wa'l-Ifta (11/113.