Fixing header fonts

Hi, I’m hoping someone is able to help me please.

I installed Hatch theme but I don’t recall the header fonts for the Blog for level 1 headings i.e. the title of the blog, “Related Posts” and “Please leave your thoughts and comments”.

At the very least if I can reduce the size of “Related Posts” and “Please leave your thoughts and comments” I will be happy. These headings seem so large compared to the rest of the text that it looks odd.

Here is a sample blog entry with the headings – http://veronicacolvin.com/2013/08/22/photoshoot-good-vs-evil-exhibition-to-support-mcgrath-foundation/

Many thanks for your help!

Cheers
vc