The Strictly Come Dancing judge was one of nine celebrities who conquered the 5,895m climb for Red Nose Day, taking on the challenge in memory of her late brother, David, who took his own life 16 years ago.
During the documentary, which aired on Wednesday night, Shirley was seen becoming emotional in the early stages of her trek.
As the group set up camp for the night, she said: “While I’m clearly struggling with the camping for sure, I’ve been comfortable in the boots, the outfit, all good, except when we came on the camp.”
She continued: “I think my brother would be proud of me. I miss him, so I’m doing this for him.
“If it means sleeping in a tent and being disorganised for a week, I’m sure I can do it, I’ll do my very best, for sure.”
Footage taken before the challenge showed Shirley meeting a man who had been helped by the charity Calm (Campaign Against Living Miserably), which receives funding from Comic Relief.
In the film, she said: “My brother took his own life. He was a young man, 44. He was like my brother, my father and my best friend.
“He was lonely, he felt low, he said he’d got into a dark hole he couldn’t get out of. I’d call him on the phone, ‘Come on David, you’re going to be fine’, because I was uneducated, so that’s why in some ways I blame myself.”
She added: “No note. No goodbye. I can only imagine 16 years ago if my brother would have had somewhere to go and somebody to talk to.
“I truly believe in my heart today he would still be here. And that’s why I’m climbing Kilimanjaro to raise awareness and help put a stop to suicide.”
Viewers of The Bigger Red Nose Climb went on to see the group of celebrities reach the summit of Kilimanjaro after a week of trekking.
Red Nose Day in aid of Comic Relief airs on BBC One on Friday.
Useful websites and helplines:
- Mind, open Monday to Friday, 9am-6pm on 0300 123 3393
- Samaritans offers a listening service which is open 24 hours a day, on 116 123 (UK and ROI - this number is FREE to call and will not appear on your phone bill.)
- The Mix is a free support service for people under 25. Call 0808 808 4994 or email: email@example.com
- Rethink Mental Illness offers practical help through its advice line which can be reached on 0300 5000 927 (open Monday to Friday 10am-4pm). More info can be found on www.rethink.org.