Also, for my brave Saturday Slash volunteers I will gladly do follow-up slashes (each more kindly than the next) on your query if you post them on the Query Critique board over on AgentQuery Connect. You'll get advice from me, and also people who are smarter than me. If you do post on AQ, be sure to follow the guidelines and let me know you posted so that I can follow up!
For Kylie Rippons changing events in time is like braiding. Except the steep cost the power demands – she must forfeit a pieces of soul. I'm not entirely sure that the second part of your hook here is a complete sentence. Also, while braiding time is a really interesting concept, you're not illustrating that here, just what the price is. I'd go with one or the other for the hook - losing bits of soul, or introducing the concept of braiding time. And, if you're going to even approach the braining metaphor, it will need some explanation within the query.
The gods want her unique skills for their never-ending wars, uncaring of the cost she must bear. But she prefers sanity so is it a spiritual price she's paying or a mental one? I feel like you're giving me two different images here. with her tattered spirit intact. The only solution is to wage war against the powerful immortals using secondary abilities, especially if it guarantees her beloved son, Riot, will remain a secret. Interesting... waging war, Ok cool. So she has secondary abilities? What are they? How would waging war against the gods help keep Riot a secret? It seems more likely to bring more attention to her and endanger him.
Two ancient goddesses, an outcast Valkyrie and a rogue Beserker nice, I like that a lot team up with Kylie to protect and fight with her. Together, they hunt the gods, in hopes of forcing them leave her alone. Too bad life gets in the way. She loses battles, is betrayed by a beloved ally, and finds herself on the verge missing "of?" being completely soulless. But I thought she was using these yet-unnamed secondary abilities and not braiding time, which is the soul-endangering ability, right?
Kylie wants her son, sanity and missing "to?" live a life of peace in the Denver suburbs. Instead, the gods learn of young Riot, a demi-god with the same power as his mother, and intend to use him as leverage. I think this is your hook -- all the way down here. Riot sounds like a huge motivator for your MC so let's get him front and center. She must face her worst nightmare: braid time and temporarily remove the threat to Riot - losing soul and sanity in the process, or find the courage to follow one bright string depicting a time line in which Riot is safe. And she is dead. So what's the difference really? She can either be insane and soulless - or dead? Assuming those aren't both the same thing?
It sounds like you have a fun idea here, mixing fantasy elements with the parental concerns - but you need to get your genre front and center as well. I was thinking pure fantasy as I read, and then suddenly Denver gets tossed into the mix and I'm all Wha? You also need to get Riot out there first - I really think that the line you've got buried in your last para is your hook. Also, the idea of changing time is tossed out there as an incidental, like Oh yeah, this is something she can do. But why does that matter? It's never addressed within the query how she does this, or why it matters, only that it's a danger to her if she does it too much.
I think there's a good concept here, but you need to get some clarification into this query about the Why's and the Where's and some How's. Some rearranging could do you wonders here in addressing a few of those problems.