What could a 11 cm spit on liver us be in a 59 yr old women, went into er for 5 day progressive illness of headache nausea throwing up, fever on day 1?

Assume cyst: I assume you meant "cyst" not "spit". Liver cysts are often benign. The cyst you describe is rather large and might cause discomfort but is likely unrelated to your symptoms. That said you need further evaluation of the illness and follow up on the cyst as there are too many assumptions about the cyst without seeing the actual report and further blood work evaluation.