Center align content of a specific sidebar widget

It is possible to center the content of a single sidebar widget? I have a text widget in which I display an image, and currently, the image is left-justified, like the content in all of my sidebar widgets. However, is there a way to center the content of a specific widget – specifically, an image? When I put the image in, I used img class=”aligncenter as I would to center an image in, for example, a post, but that didn’t change the alignment.

I imagine it’s easier to change the alignment of the content of ALL widgets via child theme – but is there a way to change the alignment for just one widget?

Thanks so much for the help.