But she won't say whether it's enough to secure her support in Tuesday's crucial vote, which will determine whether the province heads back to the polls.
With just a few days to go, Horwath says more negotiations are needed to make the provincial budget "more fair" for Ontario families.
The Liberals have agreed to deliver on two NDP demands, saying they'll increase support for child care and the Ontario Disability Support Program.
However, the government says it won't raise taxes to pay for the added assistance, meaning the money will be diverted from existing programs or offset by other cost-cutting measures.
Horwath says she is "concerned" about taking funds away from education.
"I'm not the kind of person that's a 'my way or the highway' person but I am very, very concerned and I think Ontarians agree with me," she says.
The Liberals' olive branch came a day after Horwath took one of her key demands off the table — removing the provincial portion of the HST from home heating bills.
The parties have been trying to reach a deal to avoid plunging the province into another election.
At least two opposition members must support the budget in order for it to pass, and the Tories have already vowed to oppose it.
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