My daughter had a heavy runny nose the first day; we rinsed with Aqua …

My daughter had a heavy runny nose the first day; we rinsed with Aqua Maris and saline — today seems a bit better. But since 6 a.m. she’s had a cough. It’s not dry, it’s like something is stuck. I get that when phlegm is bothering me. We went to get tests done; her blood was thick so they couldn’t take it. Has anyone come across this? Please advise ??????