Ask your mother if Jesus (Pbuh) prayed to God for help? She will tell you he did. Then ask her why she thinks if he prayed to God to help him if he could help himself? Remind her Isa (as) relied upon Allah and had no power of his own.
Mathew 27:42:
About the ninth hour Jesus cried out with a loud voice, saying, “aEli, Eli, lama sabachthani?” that is, “My God, My God, why have You forsaken Me?”
Psalm:22:1:
'My God, my God, why have You forsaken me?'
John 12:27
Now is my soul troubled; and what shall I say? Father, save me from this hour: but for this cause came I unto this hour
Christians think that Jesus died to save them. So they revere him and associate him with Allah and so believe Jesus can help them. Na udhu billah!!!!!! Your mother is swaying towards the same false beliefs. You must pull her back. Ask her if the above pleas sound like they come from the mouth of a willing participant for crucifixion? He asked God for help. Ask your mother what makes her think he could help her when he couldn't help himself? The Christian depiction of this event forms a picture in my mind of Jesus saying. 'Ahh wth, I'll sacrifice myself for the scum of this earth, but heyyy..

ffended: why aren't you helping me God?' Astaghfirullah! Does that make sense? Does this behaviour befit a prophet? To do something willingly from love and be protesting about it at the same time?
Dua is a form of worship. Ibn Taimiyyah defined worship as, "A term which comprises everything that Allah (s.w.t) loves and approves of from the apparent and hidden sayings and deeds."
“Du’a is the essence of worship”
[Sunan Tirmidhi]
And in a Qur’anic verse Allah states:
فَادْعُوا اللَّهَ مُخْلِصِينَ لَهُ الدِّينَ
“So call upon Allah making your worship pure for Him”
[Surah Ghaafir – 40:14]
It is apparent from just these two Ahadeeth that the status of supplication (Du’a) in Islam is exalted. It is an act which Allah loves and is the dearest act in his sight:
ليس شيء أكرم على الله تعالى من الدعاء
“There is nothing dearer to Allah Ta’ala than Du’a”
[Sunan Tirmidhi]
So by praying to Jesus your mother is worshipping him. Na udhu billah. May Allah guide her. Ameen. Ibn Abbas said, "the best forms of worship is the du'a" [Munthir and Ibn Haakim] He goes onto say, "Know that it is an obligation to invoke Allah Alone in Du`a, and not His creation... Admitting (and showing) humility and meekness can only be revealed to Allah, Alone, for this is the essence of worship."
Allah says of those who have passed over, "If you call upon them, they hear not your call, and if (in case) they were to hear, they could not grant it (your request) to you. And on the Day of Resurrection, they will disown your worshipping them" [35: 14]
Please show your mother this ayah: "And when My slaves ask you concerning Me, then (say) I am indeed near. I respond to the invocations of the supplicant when he calls on Me. So let them obey Me and believe in Me, so that they may be led aright." [2: 186].
This ayah alone is more than enough to tell us that we do not need intermediaries to ask Allah for help. When the time of death arrives for people who prayed to another besides Allah for helped
will be asked by angels where are they who they used to pray to. SubhanAllah! They will reply that they have deserted them.
And who is more unjust than one who invents about Allah a lie or denies His verses? Those will attain their portion of the decree until when Our messengers come to them to take them in death, they will say, "Where are those you used to invoke besides Allah ?" They will say, "They have departed from us," and will bear witness against themselves that they were disbelievers. [Al-Araf 7:37]
SubhanAllah! Please follow bro Hamza's advice and take your mother to a scholar immediately.
Please play al Baqarah with translation in your home every three days and make sure your mother is reciting the daily protective duaas and ayatul Kursi after every fardh salah. May Allah guide your mother and protect her (and us) from the shaytaan and false beliefs. Ameen.