Why would she? He effectively told her that he had killed them. Moreover, it wasn't her family so why would she try to get a taxi to pick her up to rush over to try to help even if he had called to tell her something was genuinely wrong as opposed to that he killed them which is what she claims he told her.
That is calling her makes no sense, she woudl not give a damn about them. Calling his relatives to ask them for help might make sense but not calling her.
In th emeantime claling her before police doesn't make sense which is why Jeremy lied and to this day maintains he called police first despite Reader's dishonest attempts to revise Jeremy's claims to suit Reader's agenda.
Mugford soon began to get involved
Offering to go to the mortuary
She had NO responsibility to do this
If Jeremy were guilty which I do not believe it makes her a very sick and twisted person who enjoyed the whole saga which ended up with her getting a huge bonus
I cannot believe that the British Police did not warn the authorities that she was unsuitable as a teacher
I think it was their responsibility
From the J Mugford video it looks like she no longer has a job