Go see an accountant. Whatever you are trying to do, you probably screwed up and did in the worst way possible.
1. Gift of home to daughter--gift tax requirement
When you gifted the home to your daughter, you must file a gift tax form 709. No tax is owed as long as your lifetime gifts and estate are less than $11 million, but the report is required. The value of the gift is the fair market value at the time.
2. Gift of home to daughter -- subsequent sale
You didn't say your daughter sold the home. If and when she does or did, her capital gain or loss has nothing to do with the market value. When you gifted her the home you gifted her your cost basis as well. Her gain or loss is the difference between the purchase price and selling price. Suppose you bought the home for $100,000 and she sold it for $300,000. She could have a taxable gain of $200,000, depending on whether she lived in the home for at least 2 years after you gave it to her and before she sold it.
Your cost basis on the gifted home is what you paid for it, plus and minus adjustments for improvements and business use. There is also an adjustment if you co-owned the home with a spouse who died before you, which is different depending on which state you lived in. You may need to dig through old records to determine the basis. The higher the basis you can prove with reliable records, the lower the daughters' capital gains tax will be.
3. Daughter purchased a mobile home
Why do you think there is a loss? No one has a loss. There are three completely separate transactions here. 1. You gave away a house. 2. Daughter might have sold the house (you don't say). 3. Daughter bought a mobile home. If daughter sold the house, she probably has a gain, depending on when you bought the house. Even if she has a loss, the amount of the loss has nothing to do with the mobile home. The rules about rolling one home into the other were repealed 15 or 20 years ago and replaced with the exclusion rule. Daughter's basis in the new mobile home is whatever she paid, but that does not exempt her from paying gains tax on the sale of the gifted house.
4. Mobil home is on a rented lot, and daughter pays rent to you instead of directly to the landlord.
You are either getting a gift or you are subleasing the lot and have rental income. Gift is more likely and easier to deal with and the annual amount is less than the requirement to file a gift tax return. But why doesn't she pay the landlord directly?
Go see professional please.
