If you have black French doors, you have plenty of room to install a door for your cat to enter and leave the house. If she has small glass panels with frames, you can remove a glass section of the door and install your cat. This solution will allow your cat has easy access in both directions.
Choose a glass panel at the bottom of black French doors. Several of them may have rows with three glasses. Select the one that fits you. Insert the putty knife between the wooden frame on top of the panel and glass. Hit it gently with a hammer and pry the bar to remove it from the door. The glass panel has a horizontal crossbar on top and one below. It also has a vertical left and one on the right panel. Remove the four.
Remove all nails glued to the door after removing the indents with the claws of the hammer. Pull the window panel and save it if you want to install it again. Store the bars with glass. Measure the height and width of the opening. Add 1 cm more in height for holding the cat door in place. Cut a piece of rubber 6 mm with these measures, with a stylus. A mud flap a supplier of vehicle parts also serves provided that it is malleable. Place the top edge of the cat black French doors on the place where the upper horizontal crossbar and then secure it with four wood screws 6 mm in diameter and 1 cm evenly spaced length.