My fiancee and I just got married recently. I am curious about how changing her status will affect her international travels

You forgot to tell us the most important fact: Are you a US Citizen or not? If you are a USC, make sure she files an I-131 as part of the multi-form one-step package. But, since it takes 90 days for the papers to process and for her to get a travel permit ... December travel is NOT RECOMMENDED .. in case you were wondering, NO, she can not use her F to enter the US ... she no longer possesses the required non-immigrant intent. If you only have a greencard, you have bigger problems ... you have more complicated problems. The process takes nearly 2 year and delicate timing is needed. In both situations you two should pay an attorney for a consultation.

I completely agree with my colleague and would add that you might consider checking out http://www.uscis.gov/green-card/green-card-through-family to educate yourself on the process and then consult with an immigration attorney regarding your specific situation.

What is your status? Will you be filing the applications or you will have someone represent you?

Typically when you adjust status (here, from F1 to green card), you cannot leave the United States without advance parole or green card. If she absolutely must travel in December, you may want to wait to file for her green card until after she returns. From filing a green card to receiving advance parole here in Southern California it can take between 2.5-3.5 months. So, if you will be filing for her green card in early October, she MAY get her advance parole in time to travel but she may not.

If you are a US citizen, it will take about three months from the time of filing the papers, until she can travel. She should not travel on F-1, as she may not be able to return. You should consult with an attorney. Many attorneys offer free consultations for marriage-based cases. Good luck.