A good indication of whether or not a member is still active is how the user name presents.
On Ancestry.com site, there should be an Avatar icon next to the name, with a line underneath it (hyperlinked) and can be clicked taking to the users profile.
On rootsweb.com site, there is not avatar, but the same line underneath it (hyperlinked) and can be clicked taking to the users profile profile.
The system was changed about 5 years ago, this means Maggie has not been active for at least 5 years. You can also click "view posts" next to the user name, click by *date*, this brings the users posting history up by date and you can review it for the most recent time they posted.
If you're accessing the message boards from Ancestry, you can click the username, then Profile, and review the last time the person logged on to the site. This data is not always up to date, but can give you an idea if the member has been active in the recent past.