Bella doesn't really know how long a hug in this situation should last, but she suspects the answer to that is as long as Sherlock needs it to.

(And. It's not exactly as though hugging him is some awful chore.)

"No," she says. "I probably should have been nervous at least, but I wasn't. At least not about anything he might do," she adds.

She can hardly deny, after all, that she did experience considerable anxiety during that conversation. It's just that none of it was his fault.