Yes, Mildred and Tom are first cousins, once removed. It's easy to see this if you have your data in a genealogy program like RootsMagic.... just print out a Relationship chart. I'll try to attach one, but it will probably be barely legible after converting it to what the message board will accept.
Also, you can see exactly what the relationship is between any people you've entered using RootsMagic.
For those of us with ancestors who were in Louisiana in the "early" days, we often will have very complicated relationships, double, triple, and more, because of relatives marrying relatives.
As an example, I've calculated the relationships between myself and my next younger brother, Jerry. RootsMagic tells me that we are related 157 different ways, ranging from brothers to ninth cousins twice removed and eight cousins 4 times removed.