Where do you find marnie in GTA4?

Answer 1

The first location for Niko to find Marnie in gta IV is around City Hall, Algonquin, in one of the little parks there with the fountain and hot dog seller. She asks Niko to take her to Alderney City to meet with her drug supplier.

The second (and last) place where Niko meets Marnie is just up the road from where Bernie lives on Union Drive West, Algonquin. She is on the corner by a lampost. Marnie will ask Niko to take her to the railway station in Easton, so that she can return home.

Later, when Niko checks his Emails, he will find a "thank you" from Marnie.