I've rented a house in Ohio.I was told the property was to be sold but not to worry I had 18 months.I was told to go about my business as usual.I planted my garden paid for my children's school fees (3 children) paid sports fees.less than 2 weeks later I was told you have 30 days to get out. Her reason was there was work to be done on the house before it could go on the market. Can she do this.there is no way I can find a house in the same school distric in 30 days what can I do

If the property was foreclosed you might get kicked out this quick but not just because she wants to prep for sale. Your landlord is way off base but lets assume she is misinformed before WWIII starts. Tell her you have a valid lease and it gives you legal rights to stay. You could consider giving her a chance to buy out your lease if you can find suitable replacement housing. Seek moving expenses and maybe a month or two rent as a buy out starting point. This is if you find housing and want to try this approach, you don't have to.

Month to month lease... means just that. You or landlord can give proper 30 days notice to leave. Her telling you that you had at least 18 months has no bearing since verbal real estate contracts are not valid in court.

If you have a written lease, no she can not.

If you are on a month to month rental, yes, they can tell you to leave with a 30 day notice.

Your only possible thing is that they told you not to worry for 18 months, you could possibility sue for the fact you had a 18 month verbal lease.
Not sure it will hold up in court, but that is the only chance I see,

Since if you are on just a month to month rental, they can ask you to move with a 30 day notice for any reason.