I apologize for suggesting that she had committed a fallacy here.
Can one 'commit' a fallacy?
As for the Golden Rule Fallacy, the Golden Rule states that one should do to others what one would want done to oneself. The problem here is that the others may not want done to them what you would want done to you. The assumption is that the others are like you. In some cases it will be true, but certainly not always.
The problem here is that you are not taking into account the genre of the Golden Rule. As an aphorism it is similar to proverbs in that it represents a generalisation, the plain meaning of which is clear in broad terms even though you may be able to press it to an absurd conclusion by being overly specific about the particulars of its application. It is dependent upon social context and common sense for its right interpretation and application.
In the same way, there are proverbs that are seemingly contradictory when taken out of the social context in which they separately apply. For example, "Look before you leap" v. "He who hesitates is lost".
In a general sense, the Golden Rule is simply saying treat others as well as you naturally treat yourself. The Author of the Golden Rule also said "Love your neighbour like you love yourself" and that is another way of expressing the meaning of it.
