All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.
It is impermissible to hang up the images of living beings as we have highlighted in Fataawa 82040 and 84583. Therefore, you should ask your mother to remove those pictures; and make sure that you advise her wisely, politely, and thoughtfully. You could perhaps tell her that you do not want people to see those pictures. If you exerted all effort to convince her to remove your pictures, but she did not respond, then you bear no sin for her hanging your pictures, Allaah willing.
You should know that it is incumbent on you to be kind and dutiful to your mother – even if she is non-Muslim. The best manifestation of such kindness and dutifulness towards her is inviting her to Islam and clarifying the truth to her even if you sought the help of another person to carry out that task on your behalf. Perhaps Allaah, The Exalted, would have mercy on her and guide her to Islam, and this would be good for both of you.
Ibn ‘Abbaas narrated that when the Prophet sent ‘Ali to Khaybar, he said to him: "...Then, call them to embrace Islam for, by Allaah, if a single man is guided by Allaah through you, then that will be better for you than the nice red camels (meaning the most precious wealth)." [Al-Bukhari and Muslim]
Please, refer to Fataawa 85180 and 83566 about the best ways to invite non-Muslim parents to Islam. Also refer to Fataawa 16595, 86091, 88906 and 173389 about presenting Islam to non-Muslims.
Allaah knows best.