I could detail at length the reasons why "Just Married" doesn't translate well into Klingon. Foremost among them is the fact that there are two different verbs meaning
marry --
Saw is what the groom does, and
nay is what the bride does. But that wouldn't help you find something appropriate to write, so I won't go into a long discussion of handling time stamps, adjectival verbs, sentence fragments, or anything else.
Instead, I'll suggest a concise
rIn tlhogh tay, literally
the marriage ceremony is finished.
Oh, and you might want to find a way to use the toast
'IwlIj jachjaj! may your blood scream!.
