2023 opinion
No. I don't understand why the Potterverse fandom insist on shipping Sirius and Marlene. All we know about her is that she was in the order and possibly friends with Lily. I imagine her personality as a mix of Ginny, Sirius, and Lily. I think her best friends were Sirius, Dorcas, and Lily, but I still don't ship her with Sirius. Plus, I ship wolfstar and head-canon Sirius as gay (and Remus as bi, if you're wondering), so I wouldn't bother shipping this. I also see Marlene as lesbian. They'd be amazing friends though! They'd definitely be the gay besties of Hogwarts.
Rating: 2/10.