This is not a real problem. The profiles are there, and correct. You will just need to redefine the links between the profiles.
These steps should do it (I cannot do it as they are not open profiles).
0. Write down the names of the profiles. So the part after /wiki/ (probably one of them is McGill-2441)
1. Go into your own profile, edit mode. You should see a link under your mother saying "replace/remove mother". Click that.
2. At the bottom of the page is section II: remove.
Click that bottom to remove the wrong mother.
2a. Do the same for your mother (if she has the wrong mother) and possibly other profiles).
3. Go back to edit mode. You should not have a mother now. Click the mother link. You see the same page. On the top right there is a box to enter the ID of an existing profile.
4. Enter the correct profile name for the correct mother. Hit the mother.
5. You have a mother again. Check it is the correct one and repeat the process for her as well.
6. Check the marriages. Your father and mother should be partners, add marriage (if married of course).
7. Check the mother link for all siblings. Write down which you remove and want to add. You can check: "half" next to their name means there is one different parent linked.
Hope this helps.