Margaret Lodge (Redding) - Margaret Muncaster

My name is Sharyn Lodge and I'm the great-granddaughter of Mark and Margaret Lodge (nee Redding). I have finally got around to fleshing out my Lodge family tree on GENI and I've noticed several references to a Margaret Muncaster being a daughter of Margaret Lodge (nee Redding). Most of these are connected to the MyHeritage site and I'm unable to get into that properly without paying a fee which, at this stage, I'm unprepared to do.
As far as I and my close relatives are aware, Margaret Muncaster is not a daughter of Margaret Lodge (nee Redding). The older Margaret had only 4 children - Marjery Mary Eleanor (known as Ellen) born 1869, William James born 1871, John George (my grandfather) born 1875, and Maude Elizabeth (born 1877).
As my great-great grandparents split up around the time young Maude was 10-years-old, and with the social stigma surrounding such splits at the time, it's quite possible that there was another daughter that we know nothing about. But Mark certainly never acknowledged her. He apparently spoke often of his other children, but never mentioned a Margaret.
Great-great Grandma Margaret, on the other hand, we know next to nothing about, except that it's appearing more and more that she may have been a troubled woman. At one point she was 'sent by the courts' to Mt Magdala in Christchurch which, at that time, was a home for destitute and homeless (and 'fallen') women. At the time, her daughter Maude was married and living in Christchurch, and the very fact that Margaret wasn't offered a bed by her own daughter suggests that things were not rosy between the two.
So - I don't know when this Margaret Muncaster was supposed to have been born, nor do I know who her mother was, but it's highly unlike to have been my g-g grandmother.
If anyone has any genealogical provenance of Margaret Muncaster, I would really appreciate a timeline of connections so we can get this sorted - and either added to or removed from this branch of the Lodges.
As I'm not a paid-up member of MyHeritage, I am unable to connect with the managers of the profiles on which this anomaly appears. (It does appear on sites where my son, Christopher, is manager but that's only because somebody else has added it).