What phone call does Mrs. Hudson refer to in "The Empty Hearse"?

Question

In the beginning of the Sherlock episode The Empty Hearse when John returns to 221B Baker Street, Mrs. Hudson shows a very rude behavior by slamming tea and biscuits onto the table. Why was she so upset with John?

Also she says that one phone call would have done after all that we went through. What phonecall does she refer to here?

MRS HUDSON: I’m not your mother. I’ve no right to expect it.

JOHN: No.

MRS HUDSON: ... but just one phone call, John. Just one phone call would have done.

JOHN: I know.

MRS HUDSON: After all we went through.

JOHN: Yes. I am sorry.

MRS HUDSON: Look, I understand how difficult it was for you after ... after ...

JOHN: I just let it slide, Mrs Hudson. I let it all slide. And it just got harder and harder to pick up the phone somehow. D’you know what I mean?

Source for transcript: Ariane DeVere

Answer 1

Here is some explanation of the characters so that the answer can be understood better.

There are only very few people which are close to Sherlock Holmes, one is of course John Watson and the other is Mrs. Hudson. As shown in earlier episodes of this particular series Holmes cares for both of them and is protective of them. This feeling is mutual as both John and Mrs. Hudson feel the same for Holmes.

So when Sherlock dies these are the two people which are affected and suffer most. They are like a family in that sense. As from your transcript she clearly thinks of Sherlock and John as if they were her sons.

That's why she was expecting at least One Phone Call so that they can comfort each other from the grief.

Answer 2

John hadn't been in touch with her since Sherlock's death. She was asking for a single phone call to simply find out how he'd been/how he was getting on.