Martin, who is 27 and from Main Street, Kesh, is accused of wilfully neglecting and allowing the death of her daughter Millie Martin, while her 33-year-old former partner Barry 'Budgie' McCarney of Woodview Crescent, Trillick, denies murdering and sexually and physically abusing her.
Their Dungannon Crown Court trial heard that initially police questioned Millie's mother, not as a suspect, but as a witness, following the child's death from severe head injuries on December 11, 2009.
Martin admitted to detectives that she had loved McCarney, and agreed with them that there was "nothing more important than your child's life".
When asked was there "anyone you would cover for", Martin replied: "Definitely not ....definitely not", particularly where Millie was concerned.
Millie, she told detectives, "was my life and still is".
She was directly asked about McCarney, and "would you do anything for him?"
Martin answered with an emphatic: "No."
She said her relationship with McCarney was "good" and described him as "sound", but maintained that Millie came first and that she "would not think twice" about questioning McCarney or anyone she suspected of harming her.
Martin explained that she had just "loved, loved every minute" of being a mother and bringing Millie up, and while at times it could be difficult it was "rewarding though".
Earlier the court heard that Martin had told police that when she put Millie to bed for the last time, she was "all right".
"I put her to bed and gave her a kiss and a hug and she was all right," Martin told police during a video-taped interview.
Later she added: "I gave her a kiss and a cuddle and down she goes....she is sleepy....she was still all right."
The jury of nine men and three women have already heard that shortly afterwards, Martin went out to buy a KitKat, and by the time she returned home, Millie was already being rushed to hospital.
She said she was "away literally minutes" and returned to find their home empty, and then she noticed she had "a missed call" on her mobile before it rang and it was McCarney telling her: "Quick .... quick get to the hospital ..... the child's not breathing."
"I just got into hysterics," she told detectives.
Later she described that when given the devastating news that Millie may have been "tampered with", she was "physically sick to the core".
Martin said she "couldn't believe it", and because she had no explanation for any possible sexual assault, "that's how I couldn't believe it".
Martin told police that in the days leading up to her death Millie, who loved nothing more than "getting cuddles", was her usual self, "dancing, running, walking around and stuff".
However, that last morning she was still drowsy when she wakened and her mother "just thought she was tired".
Both mother and toddler then went to her grandmother's, and while she also did not think Millie was well, put it down to the possible onslaught of flu.
According to Martin, Millie then went through a cycle of one moment "picking-up" and the next appearing sleepy and drowsy again, and vice-versa.
However, Martin also revealed that at times Millie was off her food, and she worried about her so she put her on a course of multi-vitamins.
On the evening Millie was rushed to hospital by McCarney, the child had been alone in their Glebe Park home in Enniskillen with him twice, first when Martin went to a local chip shop, and then when she went out to buy KitKat.
Martin told police when she went to the chip shop she left Millie sitting on McCarney's knee on an armchair.
Afterwards, while she ate her chips, Millie played on the floor with an empty burger box.
Martin said that normally Millie was given her supper before being washed, changed and put to bed, but because she was unwell, she only took her bottle and had her nappy changed.
Asked by police if she had noticed anything around Millie's genital area when her nappy was being changed, Martin said there was nothing to cause her any worry.
The case continues.