[One, Two, Middlesboogie]

I'm sorry to hear of your loss, Sydney.
I really don't think a cat could have got her, though; very few cats have nerve enough to tackle a fully-grown chicken. Mrs. Chicken (my mum's pet hen who lives in our garden) is only a bantam, and she beats the stuffing out of all the neighbourhood cats, many of which are at least three times her size.

Is Selma your only chicken? If so, she'll be the dominant one and will have big spurs, which make an effective weapon.