As she tells her story her voice quavers and her eyes often fill with tears: this is a woman whose simple eloquence reveals a life filled with grief and near-despair. The week's searches for the bodies of her son and the other seven "Disappeared" have brought fresh pain, but also new hope.
She says: "It's not easy to watch those big mechanical diggers. I believe the IRA is telling the truth and has given the proper information, but they can't locate the exact spot because so many years have passed. It's been quite harrowing, but it has helped that my family's all here.
"My daughter has arrived over from England with four young grandchildren so I haven't had time to sit about; we're on the go all the time, which I'm grateful for. I have great hopes, yes I do - great hopes that he's there. And we've had so much support from everyone; everyone's praying, everyone; the phone hasn't stopped ringing.
"I've thought about going down to the site, but my husband's already been there and he has advised me not to go. He said it's very depressing, that it's a scene he'll never get out of his memory. But at the same time I'm thinking that I should maybe go, even if it's only to stand there for five or ten minutes, say a wee prayer, bring a wee flower with me.
"I haven't been sleeping for a couple of nights. I even came down the stairs during the night - I was sure I'd heard the phone ringing. I couldn't believe it when it turned out I'd imagined it.
"In 1978 the IRA held Brian for 48 hours after a robbery and then released him. Brian told us about the robbery and what his share of the money was. We were very angry about the robbery and we brought him up to the clubhouse the next morning and we paid the money back again, his share of it. And we were saying, 'Maybe this is a blessing in disguise - he'll know not to do nothing like that again'.
"Brian told us about the gun. He didn't know the name of the man that give him the gun, but it was an IRA man and he was getting a share of the money. Brian was in such a state that he didn't tell us lies, I know he didn't. He was just so glad to get it off his chest.
"Brian never had tuppence. When he got his pay on Thursday he paid us all back what he owed us, a pound here and there, that type of thing. Our Brian had no right to do a robbery. He would have done it to show off. He was only 5ft 1in, so he wasn't a big, macho fellow. He was a chronic asthmatic and all his life he was in and out of hospital, especially when he was younger.
"He wasn't smart at all at school, as far as his lessons were concerned, but all the teachers were very fond of him. They used to let him wash their cars and give him half a crown, because they knew it was in vain trying to educate him. When he was 14 years old a doctor diagnosed him as having the mind of a six-year-old. He was very childish in his ways - he'd do awful silly things so we'd give him extra attention, we were all very protective of him.
"After he was taken I used to get into his bed and pull his wee bedclothes round me and eventually fall asleep. But then I'd wake up and it was a nightmare again. I'd try to get back into that sleep again to get away from it. Or I'd sit with his jacket round me; just sitting, crying from morning to night, or kneeling down and praying.
"For years I'd ring up police stations in England if I'd read in the papers that a body had been found somewhere. They'd ask me for a description and then they'd say it wasn't him.
"I wanted to jump off the edge of the world. I always wanted to run away but there was nowhere for me to run to.
"For years I was so full of hate and bitterness. I took a Sacred Heart picture off the wall and I smashed it because I couldn't believe there was a God who would let this happen. Now I pray again, every chance. Even if I'm cooking I just keep saying, 'Oh Sacred Heart of Jesus, I place all my trust in thee'.
"It has made such a difference for the IRA to own up to it and say that they killed him. That has been a comfort to me; if you can say that's a comfort, that they murdered your child. But that's the truth, that's the way I feel. I've no hatred, none at all.
"The Gardai have told us that when Brian's body is found no one will touch it and no one will know until we are contacted first. A priest will be called and we can go down there, but I don't really think I want to see that part. We have got a grave ready in a nice wee part of Milltown cemetery - it's just a dander down the road, we have all the arrangements made.
"I've got heart disease now. It's as if I've been holding on till I find Brian, just holding on to life. I believe this will be it, we will get Brian back soon."