The MatchMaker will come 3 days after your tama turns in an adult. If you paused your tamagotchi when it was an adult however, she may take longer to come.
If your tama is at the right age for the MM to come, you can set the time to 10:29am, 2:59pm, or 6:59pm. Wait one minute and the MM should come!
GotchiGirl96