Commas or no commas? Take a look at the main subject of the sentence. Is there only one of its kind? Then you need to set off the appositive phrase with commas. Otherwise, you don’t.

For example, in My mother Ethel hoed the backyard, the main subject is my mother. Is my mother the only one of its kind? Since, yes, the speaker most likely has only one mother, use commas: My mother, Ethel, hoed the backyard. The appositive phrase Ethel is nonrestrictive; it elaborates rather than identifying.On the other hand, consider My friend Ginger speaks Esperanto. The main subject is my friend; since the speaker is likely to have more than one friend, no commas are necessary. The appositive phrase Ginger is restrictive: it helps identify the friend. Of course, if the speaker is a very lonely person, he might have to say My only friend in the world, Ginger, speaks Esperanto.