The claim was made by social worker Pamela Campbell at the trial of Millie's mother, Rachael, and her former partner, Barry McCarney, on charges linking them to the little girl's death in December 2009.
Mrs. Campbell said that as she was talking to the distraught Martin and her mother, Margaret Graham, "the penny seemed to be dropping" and they began "looking back over the past few weeks".
The social worker said both mother and daughter "became angry .... calling him (McCarney) names" while at another stage "they swore about him".
Later she said that "they were both extremely distressed and very angry .....that someone could have done this to Millie .....they were extremely distraught and going over things".
Mrs. Campbell said they complained that recently when they went to pick Millie up, she appeared "to be sore around the ribs ....and that they should have picked up on this".
She added that they also told her of an occasion when Millie had a bump on her head, and that McCarney had allegedly said "she must have hit her head against the cot .... they were wondering what he must have done to keep her quiet".
Martin and her mother also allegedly told her that having thought over the past weeks other "instances had happened that they should have queried more .... they were blaming themselves for not having checked more on Millie".
Asked by Martin's defence QC John McCrudden had it seemed as if mother and daughter hadn't linked what happened to Millie as child abuse, she added: "They seemed to be blaming themselves for not having done so".
During her evidence the social worker was at pains to point out that she "can't stand over" what she was told, as she "wasn't there" to witness any abuse and was only reporting what she was told.
Mrs. Campbell said that after "the terrible news was given that 'Millie was gone' .....both Rachael and Mrs. Graham were very distressed and crying, with Rachael pleading" for Millie to be kept on the ventilator.
"Rachael just wanted her to be kept going," said the social worker, who added that "both were crying, saying they could not believe this had happened".
Full report in Thursday's edition of The Impartial Reporter.