Dear Query Shark,
Never start a query with this kind of information. Start with the book.
ROSWELL PROVISIONS is the story of a Russian divorcee who immigrated to the states at a young age.
And when I say start with the book, I mean start with the character and what changes, or is about to change in their life; what they want and why they can't have it. In other words, where your story starts.
And 140,000 words is a big ass book. It's not a deal breaker but it's a problem. Those first pages of your manuscript that you include with a query MUST be taut. When I see a big ass book, and flabby first pages, I pass.
A few months later, Aaron visits Atlanta and their paths cross again. The relationship grows deeper as they spend several romantic days together. Aside from sharing love for history and travel, they both share the pain of broken marriages. While Kate is open about her family and past heartache, Aaron keeps a veil of mystery about his family and previous marriage. This secrecy does not stop Kate from falling in love with him. The mystery gets resolved when Kate visits Aaron in Germany at a grand castle during her research for a historical novel.
There's no plot here.
You refer to a mystery, but I don't have any sense there is a mystery. That Aaron isn't forthcoming about his family or previous marriage isn't a mystery, it's How Men Are.
Right now, the problem isn't your "broken English" (which I didn't see, this reads fine to me) it's the utter lack of plot.
There are several QS entries that list guidelines for getting plot on the page. Maybe it's time for a refresher.
An effective query is most often plot focused:
a Who is the main character?
b What does she want?
c What is keeping her from getting what she wants?
d What must she sacrifice to get what she wants?/what's at stake
a Jack Reacher
b wants to see the grave of a old, almost forgotten blues musician
c when he is suddenly, inexplicably arrested for a murder he could not have committed
d When the guy behind the false arrest is also killed, Reacher can stay in town, at great peril to himself, to solve the case or he can leave shake the dust of this crazy town off his sneakers and get on with his wandering.
Your query will ALWAYS simplify the plot. (This example leaves out all references to Reacher's brother for example)
How to get stakes on the page:
e The main character must choose Path A or Path B
f If she chooses Path A, the dire consequences/outcome/peril she faces are:
g If she chooses Path B, the even more dire consequences/outcome/peril she faces are
h what will she have to give up to achieve her goal?
e When her younger sister is called to be their district's entry in the Hunger Games Katniss Everdeen must decide whether or not to go in her place.
f If she goes, her family will suffer because Katniss' hunting skills are what keeps them from starving now;
g If she decides not to go, her sister will surely die in the Games.
Hint: no backstory. Your reader will jump right in to the story with you
This will not be the exact wording for your query. It will help you distill your plot to the essentials. You need the essentials of Act One, not a rundown of the entire plot.
Thank you for your time and consideration. I look forward to your response.
To answer your question: if you're not confident of your command of English (and honestly, English is such a bitch, none of us should be all that confident) hiring an editor is a good idea. While I did not see any overt red flags here, taking an extra step is a good idea.
You can also mention at the close of your query that you're writing in English but your native language is whatever it is. That way an agent knows that if you have some oddities it's probably just English having her way with you, not that you're careless.
There are several stellar writers working in English as a second language. My favorite example is Aleksandar Hemon. His writing is often very interesting precisely because he's working in his non-native tongue. I highly recommend his books.