Remus and Sirius appreciated the sentiment, but they were furious at the trio for running off, again, but knowing that Hermione was with Harry significantly calmed Sirius. As much as he loved his godson, he trusted Hermione’s judgment above all. Truthfully, they should have known better than to leave them alone at Grimmauld, but Sirius had been knocked sideways by his own grief, and Remus wouldn't leave him to face it alone. He loved Hermione for wanting to reassure them both; but as he read her words, he was plagued by only one thought; who was taking care of her? By all accounts it should have been Remus, and if he hadn’t spectacularly fucked up their intimate conversation at the wedding, the whole situation might have been avoidable.