Does graystripe have a mate

yes, graystipe had 2 mates

silverstream was the first one, she was of RiverClan. she died bearing graystripe's kits, feathertail and stormfur *SPOILER ALERT* feathertail dies rescuing the tribe of rushing water from sharptooth, a mountain lion

his second mate was millie, a kittypet he met on his journey back to the clans she joins thunderclan and has kits: bumblestripe, briarlight, and blossempelt or fur or somthing i cant remember....anyway, hope this helps!