Hi and welcome to the forum! I am glad that I can help you.
You would like to know what kind of medications pregnant women may take during pregnancy for treatment of nasal and chest congestion due to infection.
In the first trimester of the pregnancy women should not be ill or take any medication because during this period the organs in the fetus are formed and congenital malformations, some even fatal, may appear. In the second trimester although doctors prescribe medications at times, it is advisable to avoid taking medications. Infections like colds and vaginal yeast infections may be cured. If any other viral infection such as rubella, measles(rubeola), varicella(chickenpox) appears it may harm the baby and cause congenital malformations depending on the age of the pregnancy. In the third trimester women may take medication for treatment of infections that are considered safe for the baby such as Cepaholosporins, Erythromycin and Penicillins.
Given the symptoms of your daughter's condition, she is experiencing infection with chest congestion. Because she is in the early pregnancy(beginning of second trimester) she may consider seeing her doctor and her gynecologist and consult with them both about what kind of medications she may use for her condition. She may use the medication for which both her doctor and her gynecologist will agree that is safe and useful for treatment of her current condition.
Please keep in mind that I provide medical information only. I am not able to diagnose medical conditions online. Please contact her doctor and her gynecologist for further advice and information about diagnosis and treatment options.