But the DUP leader said it should not be seen as a referendum on her handling of the Renewable Heat Incentive (RHI) scheme.
She made the comments to the BBC's Inside Politics programme on Friday.
She said Sinn Féin had used RHI as a "useful way to bring the assembly down" and re-run last year's election.
The former first minister claimed republicans wanted to weaken unionism and pursue their wider aims regarding the Irish language, Brexit and increasing the number of cross-border bodies.
She said there had been plenty of occasions when the DUP could have brought the assembly down, but had chosen not to in order to make politics work.
She accused Sinn Féin of walking away from an agreement made between the two parties in mid December on how to handle the controversy over the heating scheme.
Until mid December, Mrs Foster insisted, she and Martin McGuinness had "been working quite well together".
She said it was "absolutely wrong" to characterise her as someone who could not work with Sinn Féin and did not want to make devolution work and that after the election she would have "to try to put it (devolution) back together again".
Mrs Foster repeated her assertion that she had done nothing wrong with regards to RHI and said none of her friends or family "were even remotely connected with the Renewable Heat Incentive scheme, directly or indirectly".
She said rumours to the contrary on social media were incorrect and were "in the hands of my husband's solicitors".
Mrs Foster claimed there was now a "feeding frenzy" around the scheme, and she wishes a public inquiry had been put in place in mid December.
She also said she wishes the cost-cutting measures passed by the assembly earlier this week "had come to the fore sooner".
RHI was also the subject of an exchange between DUP party chairman Lord Morrow and Mrs Foster earlier on Friday.
In response to a comment about it being "a lovely sunny day", Lord Morrow said:  "It's hot. Yes, the boilers are all working."
Mrs Foster replied:  "Stop".
Arlene Foster has said the March election could be the most important since 1998 and would decide the future direction of Northern Ireland.