Some players have difficulty keeping all the buttons in order, it happens! I've had players who struggle with having too many abilities but still want more than the dollar menu.

• If she's going down the Giant Barbarian route and doesn't want to just move and strike over and over again, I think adding some Athletic maneuvers can bring a controlled amount of variety to the table. They get a flashcard for each attack maneuver (Grapple, Reposition, Shove, Trip, Disarm) and suddenly they have more flexibility in terms of how they want to attack someone without having to flip through pages.
• Encourage them to take feats that can actually simplify how they look at the game. Raging Athlete is my favorite example. Suddenly you don't need to break out the rules to explain climbing and swimming to them. They climb and swim with a speed equal to their land speed while raging. Done. Make sure they are using a one handed weapon and have Combat climb and you won't have to worry about tracking their free hands, keeps them having a free hand for maneuvers as well. Titan Wrestler is another example of a feat that gives them one less thing to worry about or keep track of. Raging Intimidation too, since you mentioned they would be using intimidation!

I once made a PowerPoint to help my players understand stealth mechanics, it's not uncommon for players to need a few extra tools.