Returned from Vacation and Cat hates Kitten

jsquaredv said I am currently having a problem with my Cat who is 1 1/2 year old fixed female and my Kitten who is a newly neutered 6 month old male.

Cats personality: Hands off, will come to you when she wants, only has one person and tolerates everyone else. Will bite (not hard) to let you know shes had enough but generally wants to be left alone to luxuriate.
Kittens personality: Hands on, nothing bugs him, he is fearless and will push the Cat away to eat her food and his. He is active and wants to play.

It took some time for the Cat to accept the Kitten without hissing or snarling and before I went on vacation the Cat and Kitten would take turns chasing each other and groom one another. Kitten was NOT fixed at this time. Our family went away on holiday and left our Cat and Kitten with a pet sitter that would come in and play and feed the cats multiple times per day. When we returned our Cat was dramatically yowling at the Kitten, like a screech, was growling every time he came near her. I sensed he was trying to mount her and have since had him neutered. He is home and recovering fine - being his usual happy self but every time he goes near the Cat she screams. He is not being aggressive - it could just be him being around in the same vicinity and she is growling. He is also wearing a cone which freaks the Cat out too. The Kitten is sometimes instigating the the Cats behaviour as he will come up to her while she is using the litter box, but the way the Cat screams is a bit over the top. Is there anything I can give the Cat to calm her anxiety from him - I have no idea what happened while we were away but I want the peace to come back and have them cuddling with each other again. HELP! Any recommendations would be greatly appreciated!