Actually, this in NOT the case sometimes. My 1g got the matchmaker at 2 (the tama changed at 2 also) So, the matchmaker does not come at any certain age. It will normally come at 6-10 though.
Mine came wen my tamagotchi was 8.the first time it came it brung some frankinstein looking 1. i said no. then it came with a black tall duckish thing. i said yes. then it had a baby the baby grew but was a brat so i reset the whole thing.