Selma Blair says the ''proudest moment'' of her MS journey was her son calling her ''brave''.

The 'Cruel Intentions' actress was diagnosed with multiple sclerosis nearly a year ago and admits her seven-year-old son Arthur has had to ''endure a lot'' due to her illness, which can cause problems with her vision, arm and leg movement, sensation and balance.

But it made her emotional when her little boy described her as ''not sick'' but very brave.

In an interview with PEOPLE, she said: ''He's had to endure a lot; he's seen a lot. [He says], 'Mommy's not sick. Mommy's brave.' ''

The 47-year-old actress convinced herself that her son would be embarrassed about her diagnosis but Arthur - who she has with ex-partner Jason Bleick - doesn't at all feel uncomfortable with the changes in his mother's health.

She shared: ''He said, 'I love when you come to school because you make the kids laugh and you answer all their questions.' I explain what's happening and that my voice doesn't hurt, and we have really decent exchanges, I had no idea Arthur was proud of that. I thought, 'I'm probably an embarrassment,' but to know I'm not was one of my proudest moments.''

The 'Legally Blonde' star went on to explain that she and Arthur often play games in the garden together despite her physicality being inhibited by her condition.

She said: ''We play dodge ball, but I don't dodge because that could be so dangerous. Maybe in the future for sure, but I don't move side to side perfectly, and so I get to just hit him and then he throws it back to me, really chivalrously. And then I get to hit him again, and he thinks it's amazing. I's fun and it feels good to him. To me too.''