What made harry feel a surge of pride in hermione's jinxing ability?

I believe it's because Umbridge was unable to remove Marietta's pimples after she betrayed DA. Her jinx was so effective that Marietta had it even the following year. This brings great satisfaction for harry because he always perceived umbridge to be a type of smug and know it all teacher and from the fact that MArietta is getting the payback that she deserve