3 sentences

1. 她在为考试发愁。

   tā zài wèi kǎo​shì fā​chóu.

   She is worrying about her exams.

   Source: Dong Chinese Dictionary

2. 他正在为下学期的学费发愁。

   tā zhèng​zài wèi xià xué​qī de xué​fèi fā​chóu.

   He is worrying about the tuition fees for next semester.

   Source: Dong Chinese Dictionary

3. 别为这点小事发愁，总会有办法解决的。

   bié wèi zhè diǎn xiǎo​shì fā​chóu, zǒng​huì yǒu bàn​fǎ jiě​jué de.

   Don't worry about this little thing; there will always be a way to solve it.

   Source: Dong Chinese Dictionary