Dawn reported that Rehman, Pakistan People's Party's member of the National Assembly, was appointed Pakistan's envoy to the US.
Haqqani Tuesday submitted his resignation to Prime Minister Yousuf Raza Gilani over the secret memo that was sent to Washington.
Pakistani businessman Mansoor Ijaz had alleged last month that a senior Pakistani diplomat asked for help in getting a message from Zardari to then chairman of the US Joint Chiefs of Staff, Admiral Mike Mullen.
Ijaz alleged that Zardari feared a military takeover following the US raid that killed Osama bin Laden in his hideout in Pakistan town of Abbottabad May 2.
Prior to the memo issue, the Pakistan Army and the Inter-Services Intelligence (ISI) were upset with Haqqani over issuance of visas to Americans without "prior scrutiny" by the Pakistani security agencies.
Rehman, Pakistan's information and broadcasting minister, had resigned from her post in 2009 due to differences over the government's media policy.
Thereafter, Rehman had led the efforts to reform the blasphemy law after Aasia Bibi, a Christian mother of four, was sentenced to death for allegedly insulting Prophet Muhammad.
She was supported by Punjab governor Salman Taseer and minorities minister Shahbaz Bhatti -- both of whom were shot dead this year.
A British newspaper had reported that with two of three Pakistani politicians who opposed the blasphemy law assassinated, friends of Sherry Rehman now fear for her life.
She has been advised by government ministers to leave Pakistan, the report said.