Just a suggestion, but introduce the aunt first and have her make the connection in a later session. Otherwise the whole thing may seem a bit forced and soap-opera-ish.
The ideal intro would be a session where the rogue (or the player of the rogue even) is not present - perhaps he's in jail?
Alternatively, have one of her older servants recognise the items (give the PCs a chance to notice the servant giving them a careful inspection), tell her, and the next thing the PCs know is that a contingent of the King's Guard arrives with the Consort.
A further alternative and my favourite: the goodly cleric has written to the Consort advising her that she might find the party useful and that she can recognise them through the items the rogue carries (because they'll be known only to her and a few others). Thus the whole question of provenance is bypassed; she can become their patron, and only after a good many sessions have passed can you spring the big reveal.
Unfortunately, I can't go back in time to have somebody else meet the rogue first. However, she may have somebody tag along with the party in the guise of an escort to the border of where the PCs are headed next.
the good cleric (a high level L/G cleric of Truth & Justice) will be around when the PCs first meet the king, his consort, and a few others.
