Can I get half marathon fit on the treadmill?

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Can I get half marathon fit on the treadmill?

In my early 30s, I was at my peak. I would run in the rain, no problem. I would run in the blazing sun, no problem. I would run at 9 p.m. at night – again, no problem. However, as a busy mum of two, my options aren’t what they used to be. 

Annoyingly, childcare, time of day and bad weather (getting ill simply isn’t an option) have stopped me from training for any sort of running event for the last seven years. Seven years?!