In the link you said
“There is an exception though. Sometimes a kamma vipāka can allow one to be influenced by a “malevolent being” even if one is living a moral life.”
That’s exactly what has happened!
“In such a case, it is a good idea to make offerings to the bhikkhus as well as to those who are in need and ask any such beings to accept the merits. The cultivation of Metta Bhāvanā is another.”
The thing is that my mother does Provide milk to the street dogs almost every day. Also, the preta “arrives ” but doesn’t say anything, just troubles her and leaves. So how can we ask “it”to accept the merits? This issue has been prevalent since 20 years, her age is 40. This all happened after my parents’ marriage. Initially it damaged my father’s economical conditions and the “arrival” of the preta has been seen in the recent years(around 3 years).
Is there something which can be done? It will be extremely grateful.