Dowager is the mother of Sir Topham Hatt and appears in Five Nights at Thomas's 1, mention in 2 and 4
Five Nights at Thomas's Edit
During nights 1 and 4, Dowager first appear in night 1 stop sir topham hatt go come down to eat he shut her up to stop talking but when he shut her up again she got very angry went to his room and attack him, on night 4 she can be heard telling sir topham hatt that the cop are here she gets hit by the cops, dragged her away and sir topham hatt cut the phone call because he need to save Dowager.
Five Nights at Thomas's 2 Edit
Dowager doesn't appear in five night at Thomas 2, but she is mention in night 2, 3 , 4 and 5. During one of the phone calls, Dowager is only mention by Sir topham hatt about her likes might hate him for scratch the door, she really loves him, worried that thing are gonna change in the future and if you listen in night 5 sir topham hatt just say that his mom is fat.
Five Nights at Thomas's 3 Edit
Once again, dowager still did not make appearance in the third game, she also is not mention by chuck's cousin too in one of the nights.
Five Nights at Thomas's 4 Edit
Dowager Returns in Five Nights at Thomas's 4, In chapter 2 if you go to the right on one of sir topham hatts doors you can hear her crying a lot but its unknown if she is seen anymore in the game after this.
In the video "Five Nights at Thomas's 4: Modeling Chuck's Cousin", if you pause the video at 1:48, you can see a image titled "mom.png". This could be her skin file.