Gaming and being OP

I'm going to rant, and it may sound petty, but yesterday's gaming session really irritated me. I'm new to tabletop roleplaying games, but not new to roleplaying in a general sense. I understand the basic concept of classes and stats, attack rotation, etc. I did play World of Warcraft pretty heavily for about 2 years before getting bored. I did need help with spending points and such, and since we really only had one book to use, I pretty much left a lot of my character sheet to our Game Master Jeff and John (the ex) after letting them know exactly what I wanted for my character (and they still consulted me for clarification). It also didn't help that the book is kind of ridiculously hard to follow, even for seasoned gamers.

"It reads like stereo instructions"

So, we got our characters made. John made his Corpse Candle, Kevin made his Painted Devil, and I made LaCroix. Out of us, I had the least "super powers" relying mostly on acrobatics, sneaky-sneaky, and theft (no, I'm not a Cat Woman knock-off. Cat Woman sucks). We played our merry way, had fun, my character summoned a ton of crows that skewed a battle in our favor while I used sneaky sneaky and John's character blew shit up. It was cool. Everyone said how awesome my character was and how well I played her (thick French accent and all). Jeff actually pulled me aside before a scene because I was  to be a key player. Shit was getting interesting.

Then Kevin's 18 year-old step daughter decided she wanted to join the game. So I asked her, "What's your character?" All she could tell me was he was Russian with a gas mask so I said "okay, well, Kevin has a gas mask, so you're Russian...  that's all?" Pretty much her entire character was built by Kevin, and in my opinion, he made her character so over-powered (OP, from here out) it's ridiculous. Now I called John out on being OP with one of his attacks and he scaled it back (he had actually re-read the manual and found an error with the points distribution. Like I said, horrible book). But Trina's abilities pretty much render my character irrelevant.

Case in point: Jeff is a sick fuck and had us transported to some alternate Gotham City under the totalitarian rule of people who want all metahumans to be registered and apparently hate wheels. Also everything is electric. Our team of heroes (and really, we use that term loosely...) joins the resistance and help them free Aquaman (how else are we going to get tuna sandwiches?) from a very public execution. So my character is a thief, right? I can pick locks. I'd have to critically fail to not pick a lock. Hey, all the locks here are electric, but that's okay, because I have points in technology too. I can be useful here. Trina's character can disrupt electrical fields. One BWOMP and everything electrical is disabled. Oh great. LaCroix walks Aquaman to safety while everyone else fights. Oh yeah, Trina's character defeats Superman. And that's all I fucking heard about, all day.

So yeah. Game wasn't as fun as it usually was. I don't like my character, who is actually quite developed, personality-wise and history-wise, being rendered irrelevant. I can't complain about it to my group because Kevin is her step father and his wife (her mother) hates me (she of the Facebook blocking) and John just wants peace in his house. I guess I could express it to Jeff. I was just so irritated by the end of it. I deliberately rolled a character that wasn't all-powerful. I like critical thinking and challenges. If LaCroix becomes OP in the future, it will be through plot and character development, not asshattery. The guys have already seen her lose her shit once.

Okay... Geek card shown. Breathe in breathe out before the nerdrage gets me.