Hello Kristen,
It looks like the site linked to above has WP Super Cache turned on. While you’re working on it, make sure to turn off the caching (not just disable the plugin) so you’ll be able to see the changes.
There is an option in the Styling tab of the theme options page to change the font size of the widget titles. It looks like it’s set to 20 pixels on the site right now. The text in the widget body is the same as the “body” font and size that’s set in the theme. You can change that there as well.
While I do typically include an option to change the font of the headings (h1, h2, h3, h4, h5, h6) in the themes, i don’t typically include a control to change the font-size of any of those. You’re welcome to change any of them by adding something like this to your Custom CSS:
h1 {
font-size: 48.5px;
}
h2 {
font-size: 31.5px;
}
h3 {
font-size: 24.5px;
}
h4 {
font-size: 17.5px;
}
h5 {
font-size: 14px;
}
h6 {
font-size: 11.9px;
}
Those are the defaults. You can change any of them to be size that you’d like to have and delete any of them that you’d like to leave as is.