I think the difference is that Melania meant it and Moochelle knew it was a lie when she said it. I would not be very surprised to find it was done on purpose to contrast Trump and the liar in chief
Moochie said the “limits of our ideas”...Melania said the “strength or our ideas” in one part of the disputed sections....a subtle but important difference. The disputed section is not lifted word from word though the template of the construction of that section may have been. One can have many ideas and what we can naively imagine is with out limits...but what are the “strengths’ of our core ideas and values that we strive for?
Again, a closer exam of the section reveals subtle differences; it was not an EXACT “exact” copy(read the double exact phrase with implied emphasis on the first “EXACT”). I also felt that being from Slovenia, while her command of English is very good, her knowledge of it is not perfect and she may have looked at past examples of speeches for ideas. She is probably having difficulty translating subtle context from her native language to English and probably borrowing unconsciously from the English that she has heard to help her. She should have had help but I see no evil intent here...only an innocent desire to help support her husband!