And she's staying strong through her multiple sclerosis.

It's back-to-school season, so your social media feeds are probably full of cute snapshots and happy faces. For Selma Blair, every milestone with her son, Arthur Saint, means that much more now that it's been almost a year since she was diagnosed with multiple sclerosis. According toPeople, Blair's latest Instagram post gets raw and real with the issue of Arthur growing up — but Blair isn't mad about it. She's happy to be seeing every step and notes that she's fighting to see everything the future holds for him.

The post features the two of them cuddling and sharing a sweet moment. The caption is where the feelings really come through, however, as Blair explains that she's going through what most moms are: her son getting older. She goes on to say that she admires his strength, courage, and newfound confidence.

Selma Blair Says Seeing Her Son Grow Up Is "The Best It Gets"
Credit: Axelle/Bauer-Griffin/Getty Images

"As a mom, whether strong or not so strong, I hope I can be with this child as he needs me or wants me. This is the best it gets for me. I don't begrudge him going off to school and growing up. I welcome the days as we are here now. The days seem in the correct order of things" she wrote. "Right now, I save the light I have to laugh with this one. To feel the whole day and night. But when I recover, when the bone marrow makes the amount this body needs when I rebalance my body and re-learn, I will be more present with all those I cherish."

"But now I watch as Arthur does a full flip in the pool and widen my bleak eyes in shock. When did he get so brave. It was imperceptible,” she added. "I missed the shift and then he just went and did it even as I was starting to say 'that may not be safe'. So I cheered his victory. His full on confidence. And it was from a great height."

Blair has been open about her diagnosis, symptoms, and how she and Arthur are handling everything. She mentioned that he's seen her fall down the stairs, struggle to be mobile, and rush to the bathroom when she's feeling ill.

"He's had to endure a lot; he’s seen a lot," Blair told People. She added that she's living with a positive outlook so that she can be there for her son and set an example that he can follow.

"This is it. The only life we get," Blair said. "My disease isn't a tragedy, but I tell myself, 'You're going to live in a way that would be an example for yourself and your son.'"