What are the power of prayers? If someone else prays for you, are you eligibile to reap the benefits of their prayers. What then determines your eligibility? This is similar to the thought that if someone thinks ill of you, will their negative thoughts have any impact on you. In both these situations, whatever your receiving powers are, you will receive accordingly. If and when someone is saying these unpleasant things about you, and you are overhearing this, and letting it impact you, then it will cause bad to you.
When someone is praying for you, like your mother, father, older sibling, spouse or well-wisher, then you become your humble listening to their blessing and sit down in a poised manner to receive them. If your gesture or behavior matches with the frequency of their blessings, then you will surely benefit from them. But even here, your demeanour matters very much. If you are receptive to their blessings, then you will surely be blessed because of it. But if you have a bad attitude, and sit there with arrogance, then the blessings will not reach you.
Imagine if you wanted to fill a pot, but you have placed it upside down and you are trying to fill it. You may even empty the whole ocean, but the pot will remain unfilled. But if you set the pot right side up, then in a matter of few minutes the pot will become filled with water. Therefore, how your behavior is, how your mood is, how receptive you are will decide if you will receive the fruit of others blessings. If you want to be blessed, then you need to become receptive to blessings.
You can even apply this same principle to the situation where someone is speaking ill about you. Use your shields to cover, and protect yourself thereby blocking off any negativity. Depending on whether you want something or not, close or keep the doors of your heart wide open.