Trump is due to land at Dublin Airport on Saturday morning before flying west to Shannon and traveling on to his golf resort at Doonbeg, which is hosting the Irish Open this weekend.
The woman's original plan was to protest outside the resort itself, she told Today FM, but she abandoned it once she understood how tightly the area would be sealed.
"I was going to go down and try and protest down there, but I'd say we wouldn't even get near it. So we just said we'll do this instead," she said.
Ray Foley asked her during the interview whether the house was actually in the flight path, and she said that it was.
It took weeks of persuading her husband, Paul, to help, she said.
"I've been troubling him for a long time to do this, because we knew he was going to be coming," she said, adding that she kept needling him until he gave in.
The finished letters spell out "F— TRUMP" and dwarf the house beside them, according to the Daily Beast, which reported that the sign stretches across the entire field.
A second message appeared on Thursday on a beach in Dublin Bay, under the approach to Dublin Airport, RTÉ reported.
The campaigning organization Uplift carved the words "NO KINGS — GAZA IRAN ICE" into the sand, the broadcaster reported.
Waterford environmental artist Seán Corcoran designed the piece using rakes, according to RTÉ, and Uplift said it chose sand so the work would vanish with the tide.
"We want to send a message to Trump that he is not welcome here in Ireland," Uplift executive director Siobhán O'Donoghue said in a statement.
"We chose sand to drive home the message that Trump's administration will one day be history," O'Donoghue said.
Both messages were finished ahead of a shutdown that An Garda Síochána has described as "one of the biggest policing and security operations" it has ever mounted.
The force has declared an extraordinary event, and officers will work more than 10,000 12-hour tours of duty between Friday and Sunday, the Press Association said.
The Phoenix Park in Dublin was sealed off at 11 p.m. on Thursday and is expected to stay closed until 6 p.m. Saturday, RTÉ reported, closing Dublin Zoo and the Magazine Fort to visitors.
In Clare, access to Doonbeg village and stretches of the N67 road is restricted, the broadcaster reported, and drone flights are barred near Dublin Airport. The Irish Aviation Authority has placed temporary restricted areas over Shannon Airport and the Doonbeg course, and a maritime exclusion zone is in force off Co. Wicklow.
"We have robust policing plans in place and will arrest and prosecute those committing offenses," Garda Commissioner Justin Kelly told reporters on Friday.
Justin Kelly also said there would be "no tolerance" for public disorder, and that the force's water cannon would be on standby, according to the Press Association, though he said he hoped it would not be needed.
Gardaí have said they will facilitate peaceful protest, and several demonstrations are going ahead, RTÉ reported.
The Irish Neutrality League plans to assemble at the Garden of Remembrance in Dublin and march to the GPO at 1 p.m. Saturday, the broadcaster reported, with further protests at the entrance to Shannon Airport, at an agreed location in Doonbeg village, and in Galway city center.
"We hope to give Trump a great big unwelcome when he arrives in Shannon on Saturday morning," Futureproof Clare member Sinead Sheehan told the Clare Champion.
The Trump Organization's Boeing 757 touched down at Shannon shortly after 6:30 a.m. Friday with Eric Trump aboard, Clare FM reported, and a cavalcade of Garda and U.S. Secret Service vehicles reached Doonbeg about an hour later.
The flight path message can be seen here.
