My mom is coughing a lot???

by the way I'm 12 and my mom is 54 and she had bronchitis in December of 2007 and it went away in like 6 weeks and I had a cough the doc said it was posnasal drip and gave me medicine but I had it overall a month to 6 weeks. The bronchitis effect of the cough is coming back (the cough, not as bad though). Should we be worried? She's been coughing maybe for a week now but the bronchitis went away and she had a prescription for it but that went away long ago. And its like April almost its spring! I mean she can't have bronchitis with warm weather can she??? What does she have-she doesnt smoke nor has never smoked please help thanks! =)