The 17-year-old tragically took his own life last weekend and will be laid to rest following a ceremony at the Newlands Cross crematorium on Thursday.
In a message posted on her Twitter account last night, Ms O'Connor said her son, who was a Hindu, wanted just his parents to attend his funeral - a wish he tragically expressed in notes before he went missing from hospital last Thursday.
"Shane was Hindu. So the funeral will be just his mother and father," she said.
She asked that if people are going to send anything to the mortuary at Loughlinstown Hospital or Newlands Cross crematorium, to "please send flowers or Hindu objects."
Ms O'Connor also raised the issue of a lack of mental health services, including beds in special care, for teenagers, writing "we are a third world country."
On Saturday, Ms O'Connor (55) confirmed on Twitter that her "beautiful son" whom she described as the light of her life "decided to end his earthly struggle."
Meanwhile, an independent review panel will investigate the circumstances surrounding Shane's death. A missing person search for the 17-year-old was stood down on Saturday after his remains were discovered in Bray, Co Wicklow.
It is now expected a series of inquiries will get underway.
Gardaí are assisting the coroner in preparing a file for the inquest, while the National Review Panel (NRP) - which examines serious incidents including the deaths of children known to child protection services - will also investigate his death.
On Monday, the singer said her son had previously left notes, including detailed funeral plans.
"Shaney, babba, stick with me. Wherever you may also be, please stick with me. My baby, I don't know how I'm going to live without you," she wrote.
"I would like to thank all care staff at Riverside for the love you gave Shane.
"You did your best at all times. He loves you for it and so do I. Be at peace." She also thanked Shane's father, Donal Lunny.
"You did your best too, Donal. And Shane adored you," Ms O'Connor said. "And I will always remember how sweet you have been to him. You have been a lovely father. I am so sorry for your loss."
There has been a huge outpouring of support for Ms O'Connor and her family.
Pogues singer Shane MacGowan said he was praying she can be comforted and find strength following the death of her son.
"Sinéad you have always been there for me and for so many people, you have been a comfort and a soul who is not afraid to feel the pain of the suffering," he wrote. "You have always tried to heal and help.
"I pray that you can be comforted and find strength, healing and peace in your own sorrow and loss. He was a beautiful boy and I loved him. I pray that he can be at peace and also be able to stay connected with you. Love, Shane."
Billy Redmond, principal of North Wicklow Educate Together Secondary School in Bray, where Shane attended, said: "It is with profound sadness that the Board of Management, staff and students of North Wicklow Educate Together Secondary School have learned of the tragic death of Shane O'Connor, a past student of the school.
"The school's Student Support Team is offering support to the students in school as appropriate. Our sincerest sympathy is extended to the family and friends of Shane at this difficult time."
If you have been affected by any of the issues raised in this article, visit www.independent.ie/service/helplines-40487532.html or contact Samaritans by calling 116 123 (freephone) or emailing email@example.com.