So I took the plunge and signed up at ScotlandsPeople, the "official government source of genealogical data for Scotland" yesterday. I was waiting for a clear-headed moment (they come so rarely) because I knew that ScotlandsPeople charges not only to download documents, but also to see search results.
But a blog post is fine motivation, and I decided I'd waited long enough to find Janet McFayden McFadgeon, McFadyen, etc. etc. etc. I know from research on my own flourishing Scots line that Jane, Jean, and Janet get used interchangeably.
The results are a bit disappointing, although I win a bet with myself for yet more variant spellings of the surname. Her bdate of 5 Feb 1828 was pretty consistent in other records, but there's no one in her county on that date. Line 9 is the closest match for location and lines 6 and 8 are closest for (baptism) date. I'm inclined to go with line 9, Jean McFadzen because other family members are in that county and no one has turned up in Argyll or Wigtown.
But work on my husband's gg-grandmother Janet Jane Jean McFayden McFadgeon McFadyen McFadzen will continue.
The search was structured for all female births in 1828 in any county for surname McFadyen (using Soundex) and first name starting with a J. (James and John snuck in there anyway.)