Date is set for West Tyrone by-election
The Westminster by-election triggered by the resignation of Sinn Féin's Barry McElduff will be held on 3 May.
It was uploaded to social media on the anniversary of the murders of 10 Protestant workmen by the IRA in Kingsmills.
The former MP was initially disciplined by Sinn Féin, but he subsequently resigned from his seat.
The 26 year-old is the daughter of Seán Begley, a long-serving Sinn Féin councillor on Omagh District Council.
Other candidates for the seat have yet to be revealed.
A DUP spokesperson said the party is "aware of the forthcoming by-election and will have further comment to make in due course".
The Ulster Unionist leader Robin Swann previously called for a non-partisan candidate to contest the seat against Sinn Féin.
"Given the hurt that has been caused to victims by Mr McElduff's actions I think it is important that the by-election provides them with a voice.
"If a candidate emerges that allows cross-community support to coalesce around, it would send a strong message that this type of behaviour will not be tolerated," he said.
The SDLP has not selected a candidate yet, but Daniel McCrossan who contested the seat last year said he believes a candidate will be ratified before the party's conference at the start of April.
"The SDLP will be fighting this election on all fronts. We will be offering voters a pro-European voice in Westminster by taking our seats and challenging the DUP and the Conservative government," he added.