I would guess that you are asking the wrong question.
Can you run 2 marathons in a month? Yes. You can run two marathons in a weekend. And no, I am not talking about me, or a hypothetical well trained runner, I am talking about you.If you can run a marathon in 5 hours, it would be very reasonable to assume you can run 2 on consecutive days running them in maybe 6 - 6,5 hours each. So, running them a month apart, maybe 5:30 for both of them, shouldn't be a problem. Please note that BOTH marathons have to be run in a signifficantly slower fashion than your current capability.
Coming back to my initial statement: Is this really what you want to do? Or is your question rather: Can I have two great marathon performances within 4 weeks? In which case - and I hope you don't mind me being frank - , taking into account your lack of experience and not stellar finish time, I would say: No. That is probably not a good idea.
Best,
Stefan
... who will run Frankfurt marathon on 10/28, Dublin on 10/29 and NYC on 11/4 ;-)