The daughter of Commons Deputy Speaker Sir Lindsay Hoyle had been in a "toxic" relationship before her death, an inquest heard.
Natalie Lewis-Hoyle, 28, died in Heybridge, Essex, on December 15 last year.
The young parish councillor was described as someone who had been full of life and had a "whole bundle of energy", at the hearing in Chelmsford.
She had been reflecting on a troubled relationship before her death but was "finally coming to terms with the fact that it wasn't going to go anywhere", her mother Miriam Lewis said.
Essex police concluded there were no suspicious circumstances and had been no third party involvement in Miss Lewis-Hoyle's death, and this was accepted by the court.
But both her parents, who attended along with their partners, said they were troubled by phone calls they believed had affected their daughter's state of mind.
They said she had expressed no intentions to take her own life.
Miss Lewis-Hoyle had been collected by her mother from Hatfield Peverel railway station on December 14 and had a blood alcohol level of 171 milligrams per 100 millilitres.
Coroner Caroline Beasley-Murray said she wanted to put that in context by adding that "she wasn't driving and it was a week night before Christmas" when many people went for drinks after work.
Mrs Lewis found her daughter hanging at home the next morning and she was pronounced dead at 6.46am.
Sir Lindsay, a Labour MP for Chorley in Lancashire, said he believed what happened had been "a reaction to that phone call" adding the call "had left somebody in a different state of mind than what they had been in (before)".
Mrs Lewis, who is a Maldon district councillor for the Conservative Party, said: "I'm afraid for me I accept that within the law as it stands at the time there was no third party involvement but it's not something that I am going to be able to put out of my head."
She said there had been an "attack", the details of which were not given, a few weeks before at a time when her daughter's relationship "was really, really deteriorating".
The coroner said: "She was in a somewhat troubled relationship."
Mrs Lewis responded: "A very toxic relationship."
Mrs Lewis said of her daughter: "When somebody is in psychological torment you don't get the bruises and the fat lips and the black eyes."
Mrs Beasley-Murray recorded an open conclusion, at which point Miss Lewis-Hoyle's parents comforted each other and Mrs Lewis said: "Thank you."
The coroner added: "We haven't got all of the bits of the jigsaw.
"We will never quite know what was going through her mind.
"So that's what I am going to record."
Miss Lewis-Hoyle had been chairwoman of the environment committee at Heybridge parish council, and was "clearly much loved", the coroner added.
Her father said: "She was a person that loved life. She was life. She brought life to everybody."
Referencing her daughter's small frame, Mrs Lewis said: "She was a tiny person, a teeny tiny person.
"She was a pocket rocket. She was just a whole bundle of energy."
Mrs Beasley-Murray expressed her condolences to the family.