If you inherit the property through will after her death you do not have to pay any taxes. If you sell the property after having inherited it, you may have to pay capital gains taxes. But they will inherit the property at the value on the day of her death. Thus, if you sell the property almost immediately after inheritance, you pay almost no capital gains tax as your profit in that case would be negligible.
On the other hand, if you get the property ownership pruor to her death, the tax basis of the property would be the price at which she had bought it. Thus, when you sell you gain more profit and therefore, are liable to pay more capital gains taxes. This is why my suggestion would be not to put your name on the deed prior to the her death.