My mother is dying im a atheist not looking for religious debate or to be converted respect everyones beliefs but looking advise from christians as other non christians might not understand this isnt about pandering to someones beliefs should i lie to my Mum say ive become a believer

My mum and me never had much off a relationship since i left home at eightteen as a atheist. She was very ocd with her religion. My childhood was pretty much reading bible praying going church nothing else wasnt allowed friends, tv. games toys or anything that distracted from god. Any conversation that not about god was banned. My brother died from cystric fibrosis seven years ago he was a atheist too. I made effort to keep in touch with mum shed only speak on phone because she couldnt be in presence off a non believer she said some very harsh things about my brother after his death which drove me away from her not going to go into them She never went out apart from church once week wouldnt come to my house because i tv and worldly items and used internet. Her religion was very ocd i think there was always some kind off mental health involved but there was no encouraging her to get any kind off health i wasnt welcome home as soon as i came out as atheist and asexual. She saw me as worshipping fake gods because i have pets i adore She saw me as sinner because im asexual which means i never had a partner never sexually active didn't want partner or children she saw it as same as gay lesbian against gods will Im a intervert and spend life loving my pets living alone staying in never been a drinker or drug user never been in relationships or partied yet she saw my disbelief not been married as so shameful she couldnt be in my presence None off that matters now shes dying and i still do and always have loved her and ive been home a few times. Shes in great fear off been not right with god because she had two atheist children do i lie to give her some comfort one thing she always raised me to me a very honest person but i want to calm her fears. It kind off hurts too that shell never accept me for who i was and she still makes comments about my brother that i wish she wouldnt but its not about me right now. Is lying doing more harm than good