How do I explain this to my 7 year old?

I've been so sick I can barely get out of bed and throwing up constantly etc. we just told my daughter, I don't want her to think its baby making me sick so then she doesn't like the baby! Am I worrying about nothing? I also don't want her worrying about me being sick???
Any experienced moms have any advice??? My 7yo is technically my step daughter but i have raised her as my own since she was 3 bc her moms not in her life so just nervous all around about adding a member to our family.