To be seriously disgusted with my friend?

[DevotionAndDesire]

I have become friends with the mum of a boy that my DS went to nursery with.
Her DS is the same age as mine, 4 almost 5.

I found out this weekend that she 'occasionally' leaves her son alone on a night when his is in bed asleep.
To me this is compleatly unacceptable, and I told her so.
But she argued that it isn't for long periods of time and that once he goes to bed he is 'dead to the world' and has never woken up during the night.
She also said that she wouldn't leave him alone during the day, it is only when he is asleep and 'safe in bed'.

I just can not believe that she thinks that this is okay, but after speaking to another friend with a child of a similar age she didn't seem to think it was that bad.

Is it just me or AIBU to think this is terrible parenting to leave a 4/5 year old home alone whether they are asleep or not for any length of time?!?

"Really? I can't nip upstairs for a crap while the kids are in the garden?!?"

I still don't get to poo in peace, and mine are 7 and 9. So when they were four, um, no there was no chance of them staying in the garden while I went to the loo. I believe this is a common pattern.

I must admit I do poo in peace, because i lock the door! not to say that I don't get knocking and little voices saying "mummy, what are you DOING?!" and little eyes gazing through the keyhole at me

Would NEVER leave a child alone during the day or night - nothing is that important, and if it was an emergency i'd ring a friend or ask a neighbour to come and sit downstairs till i got back.