The owner of Memories Pizza, Crystal O'Connor received death threats and was forced to close the restaurant after saying she would not cater for gay weddings.
The devout Christian says she stands by her comments – that she does not hate gay people, but does not support gay marriage.
"It is not a sin that we bring gays into our establishment, and to serve them. It is a sin, though, if we condone. If we cater their wedding."
She told Fox News: "We feel we are participating, we are putting a stamp of approval on their wedding, and we cannot do that."
However, the Memories Pizza owner who described the business as a "Christian establishment", said she would still serve gay customers.
The crowdfunding campaign was launched on the GoFundMe page, contributor Lawrence Jones wrote that he and several producers set up the campaign to support the couple.
"The intent was to help the family stave off the burdensome cost of having the media parked out front, activists tearing them down and no customers coming in."
The campaign has so far raised more than £564,000.
The O'Connors faced a storm of criticism after they told local media that they supported Indiana's Religious Freedom Restoration Act. Critics have warned that the controversial law, passed last week, could allow for discrimination against the LGBT community in the state.
Indiana Governor Mike Pence signed a bill on Thursday clarifying that the law does not allow businesses to use religious beliefs as a reason to refuse to serve gay people or other minority groups.
The law "has become a subject of great misunderstanding and controversy across our state and nation", he said.
The group Freedom Indiana, which has campaigned against the bill, said in a statement: "We won the battle today, but we haven't won the war."