Header is not an option under the Appearance menu

Earlier this week, I made a change to my functions.php file and it crashed me entire website. A .php expert fixed it for me and my site came back up; apparently I was missing a bracket or something. When my site was back up, the header was missing. I didn’t think much of it; I knew it wouldn’t be too hard to add. I went to upload the header image yesterday, and noticed that the Header option is no longer available under the Appearance menu. The .php expert is out of town for the next month, so I was hoping someone on here could help me fix this. I’d rather not change anymore .php files because of my terrifying experience last time changing the functions.php file. If anyone has any ideas, I’d really appreciate it! My site is http://www.mattandandreaswedding.com.

Thank you!