She’s wearing a wedding ring so the assumption can be made they got married sometime after Ghostbusters II. Dana tests Peter’s ESP ability with the same cards he once used to test his students ...

During the sequence, they’re playing with the ESP machine that Venkman uses in the first Ghostbusters film ... his extrasensory perception using cards with shapes on one side that Venkman ...

Ghostbusters ... them in their apartment playing with Venkman's ESP machine, which he used in the original on his students. Dana is holding up cards with drawings on them that only she can ...