That's really weird. Usually the Matchmaker comes when your Tama is 6 or 7, not 8. I say try setting it to either 10:29 a.m, 2:59 p.m, or 6:59 p.m and wait 1 minute to see if the Matchmaker comes. If she does, then you're all set!! If she doesn't, then just keep watching for her around those times each day.
P.S. Sometimes, setting the clock to 2:59 p.m and waiting 1 minute for the Matchmaker doesn't work. I dunno why. But I'm pretty sure the other times work fine!!