Thanks for your quick reply. Unfortunately, I'm not a paid subscriber to ancestry, and can't access your information, but I can log in for messages etc. I do have some interesting information for you, if you can access it. A man from the United States has been researching our family tree, and I have contributed some. He has done a lot of work on the family members who moved to the United States - Agnes, who married a McGovern, and Mary Lizzie, who married a Parsons. The work he has done is called the McGovern-McDonald (MacDonald) family tree, and it's on the ancestry site. I don't know if you would have access or not as an Ancestry.ca member, but you can try a search. The man doing the research isn't a relative, but a good friend of the McGovern family. There are some good pictures there, in particular your mother's first cousin, Horace Parsons.
Also, I have this website that's mostly about Kate's family. Most recent information is incomplete in places, and dates may be off a bit, but the information from generations back looks really good. http://www.macdonaldfamily.org/Laughlin_McDonald.htm
I hope that this is helpful. I look forward to further correspondence. Who knows, maybe we'll crack the Alexander McDonald mystery?