I had the same thing... it took me like 3 weeks to get over. She needs to get checked by a dr, in case she does need antibiotics... but I do know mucinex is safe, my doc prescribed it for me to help with both the congestion and headaches.
If there is any discoloration to her mucus then amoxycillan or a z-pack may be necessary, if it's clear mucus antibiotics won't help....NO sudafed...nothign containing phenylephrine or spuedoephedrine during the first trimester as it can cause problems taken during that time, it's fine to take AFTER the first trimester BUT pseudoepehdrine raises your blood pressure....claritin is waht they usually give, but doesn't always work....there's a sinus rinse you can get at walmart...I used it, helped SO much and it's completely safe...non-drug....it's made by neil med. I ALWAYS have sinu problems but they are multiplied during pregnancy.
I suggest she get a script for Amoxycillin (sp?).. that's what my dr. had me take for a sinus infection, and it's safe. it worked MIRACLES