The announcement was made as the families prepared for a special Mass to mark a month since her death.
Her loved ones said that they hope to establish a charitable trust in her name which they believe could become a force for good.
Her husband John said his late wife had inspired him to be a better person.
And her father, Tyrone GAA manager Mickey Harte, said he hoped a charitable trust established in his daughter's name could have a positive influence in the aftermath of the outpouring of grief over the tragedy.
Mr McAreavey, a Co Down Gaelic football player, said: “From the enormous amount of support and kind words I have received from people in response to the tragic loss of my beautiful wife Michaela, it has struck me the way she lived her life has had a profound effect on many people.
“The values that embodied Michaela's life seem to have captured the public's heart. For people to be aware of just how beautiful Michaela was in this regard fills me with joy and pride.
“I am eternally grateful and privileged to have been such a large part of her life and this alone helps console me during this difficult time.
“Many people have encouraged me to act on the positive lifestyle and morals that Michaela enjoyed in her life. She has indeed had a major positive impact on my life in this regard also.
“She inspired me to live my life to the full and supported me to be the person I wanted to be.” Mr Harte said public support was helping his family deal with the burden of their loss and he hoped the same goodwill could be used to help others by forming a charity in his daughter's memory.
“I continue to be amazed on a daily basis at the reaction there has been to the untimely death of our beautiful daughter Michaela,” he said.
“The fact that she has touched the lives of so many who never knew her but now feel that they do, has encouraged both families, Hartes and McAreaveys, to put in place the formation of a trust/foundation to celebrate through her the sound values which Michaela held dear.
“The prayers and deluge of cards and letters which we have received has been a huge source of comfort to us all and clearly indicate that Michaela's principled and vibrant lifestyle has resonated with people of all ages and creeds in this country, and indeed throughout the world.
“Therefore we feel it is appropriate to commemorate those positive attributes in a way that may in the future influence others for the good.”
Five men have been charged in connection with the murder of the young Irish language teacher while she honeymooned on the Indian Ocean island of Mauritius last month.
In a joint statement the McAreavey and Harte families also said: “Thank you everyone that contributed in any way, small or large, to the organisation and logistics of the wake and funeral.
“We have been overwhelmed with the volume and sincerity of support from people from all sides of the community across Ireland and the entire world.”
The families said that a month's mind Mass will be held in St Malachy's chapel, Ballymacilroy, near Ballygawley in Co Tyrone, on Friday night at 8pm. The service will take place in the same church where the young couple were married just after Christmas and where Michaela's funeral was held.
The families also expressed their thanks for donations made in lieu of flowers to the Spirit of Paul McGirr fund and the Cormac Trust, two charities commemorating Tyrone Gaelic football stars who also died tragically. The bereaved relatives said further details on a foundation or trust in memory of Michaela would be announced at a later date.