At this point, when you're writing your own novel, you might be tempted to think "YAY! I have a first chapter!" and then jump up and down.
Don't do that - people will think you're weird. And, since you're writing a book, there's a 99.999999999999% that you're sitting at a table inside Starbucks with your MacBook open for all to see while you brood and emote. Jumping up and down in this scenario will lead to coffee spillage and stained clothes, if not burns. (People think writing's all safe and stuff, but it's really quite the dangerous undertaking.)
Seriously though, what you've most likely got on your hands is a *potential* first chapter that's mostly character sketch rather than plot. In the case of my example opening, we now know a lot about the main character, and a little about a few of the others. For a novel to function, we've got to get out of that main character's head and find out about everyone and everything else. And yes, it's possible to do this, even in first person present tense. This is where you start to focus on: CONFLICT.
Conflict is what drives the plot. It's the shove against the wheels of your story machine that keeps it rolling, and there should ideally be conflict in every chapter.
Does this mean that your character has to be engaged in a fight or flight scenario on every page? No. It means that she needs to keep moving. The signs can be subtle, and they don't have to be violent.
In the example chapter one, there's implied conflict between the main character's parents, as well as conflict between the main character and the changes that have been thrown at her. We know her parents aren't together, and we know that while London's mother seems to still care about her father, she never passed along the gifts that the father sent. We know that London is fighting circumstance by using her school uniform as armor. We know that London can't quite bring herself to add the 'mother' to stepmother, and thinks of "step" as a nickname for Stephanie to rationalize it. Those are all conflicts to either be resolved or continued throughout the story.
Going into a second chapter, you'll need new conflicts to add to the existing ones, and since the main character is going to be interacting with the family she's never met - for the first time - there will be ample opportunity. What's left to decide is how intense this conflict will be, and how easily resolved it becomes. Sibling rivalry can always be intense, but imagine how different it is when the siblings don't know each others' limits, or what buttons to push to get a reaction. Imagine the fear of a girl with a stable family suddenly having an outsider thrown into the mix, maybe even vying for her dad's attention or her younger sister's. Imagine the fear of the outsider disrupting the normal routine and wondering if everyone she sees secretly wants her to leave.
The answers to those questions (or the ones most appropriate to your own endeavor) will frame the next step of the main character's journey. Here's where the other characters will begin to solidify, and you'll get to show off their personalities. Determine if the characters in question are the type to actively make a bad situation worse, in hopes that the offending element will remove itself, or if they're trying to do the right thing, but it's still not working right. Conflict can exist even in a scenario when everyone is a "good" character.
Just remember that the key is movement. Readers don't have visual cues like you get with a movie or television show; they need the cues and clues you provide to fill in their imagined versions of the world you've created. So long as you keep up the struggle, they've got something to hope your MC triumphs against (or loses to, if your MC is the villain). Conflict in fiction isn't a bad thing. It's the driving force behind your narrative.