You should owe no taxes on the sale. Just getting a 1099 does not mean you owe taxes, just that you have to report the sale, and pay taxes if there is a profit on the sale.
Property received as an inheritance gets what is called a "stepped up basis." That means that it is treated as you having "paid" the amount it was worth on the date of death of the person from whom you inherited. So, unless you sold the property for more than it was worth on the date of death, you will not be...
You should contact an attorney regarding this matter. It is possible that the bank account was joint tenancy with the right of survivorship. If so, and if it was properly done, the money could legally belong to your sister.
It is also possible that your sister used the power of attorney to set up her signature on the bank accounts. If this is the case, she should not have a claim to all of the money. See an attorney to have this checked out immediately.
Probate law in the United States is state specific (It can be different for each state), so your question would get better answers if it were posted as a New Jersey question.
Since the will was drafted by an attorney in New Jersey, it probably meets all of the requirements of a valid will. That would mean that it would have to be proven that the will was signed as a result of fraud or undue influence. In most states, that would be very hard to show, especially since most attorneys take...
Were you dealing with a real estate salesperson who was representing you on the purchase? They should have been on top of this, and may have some responsibility.
You could argue that the seller received notice on the feasibility acceptance because of the follow through on the other conditions, but you may have waived any rights by "agreeing" to the new sale price. In short, you need to take the paperwork to a real estate attorney, and follow the attorney's advice.
You may not be able to get reimbursement. You were not legally liable for her funeral costs.
If she had any assets, you could start a probate and present the bill to be paid from the assets of the estate. However, from your statement of facts, it seems that she might not have any assets worth probating. If not, I know of no way for you to be reimbursed, unless you find a relative who is willing to volunteer to do so.
While I agree with the other answers to this question, I write to add that, even if there is a will which leaves you nothing, you would still be entitled to make a claim for an award in lieu of homestead from the estate. This may help a little in that situation, at least if he has any assets to probate.
You should contact a probate attorney immediately.
The proper time to settle this issue is now, before the marriage. You should discuss what each of you wants to have happen to your estates in the event of your death. Then each of you contact an attorney and get legal advice, and sign a pre-nup.
That said, what anyone wants to leave to their children is totally up to them, as long as they are legally competent and not under undue influence. No child is entitled to inherit anything from their parents just because they are a child.
You don't say where the property is located. If it is in Alaska, then an Alaska attorney should be consulted to determine the consequences of this transfer.
If the property is located in Washington, you may find that the transfer is subject to real estate excise tax (1.78%), at least to the extent of the balance owed on the mortgage.
Your question also raises the issue of gift tax. Depending on the value of the equity in the property there may be gift tax and/or lifetime exclusion use...
First, you are not required to become her guardian, but you probably may, if you wish. You first need to determine if your parents were appointed by the court, or if this was just an informal arrangement.
If it is a formal guardianship, the procedure would be to petition the court handling the guardianship to be appointed successor guardian. The qualification is not very difficult, but some people don't qualify.
Depending on her degree of disability, you might be able to get by with a...