To be annoyed about this?

OP kindly I think you are projecting here, and blaming babysitter for issues that were either not her fault, or arguably yours.

Yeah, all a bit weird

Apart from anything else OP, you have contradicted yourself in what you've said about her finding your house. First of all you said 'she couldn't find my house even though she was down the right road. It isn't obvious as such as lots of houses and not clearly marked so was a little surprising.' Then later you said 'It's a bit tricky I guess to find the house but the doors are all labelled with numbers clearly displayed. Are the houses clearly labelled or not? If not, then it's hardly surprising she couldn't find it easily, and was flustered about being late.

You also say 'My friend, the child's mum was fine with using the sitter. Obviously I didn't make that decision off my own back'. I'm afraid there was nothing 'obvious' about your having discussed the situation with the child's Mum beforehand, because you didn't tell us.

Personally, I think you were more of a failure in this scenario than the babysitter. OK the appointment happened out of the blue, but surely it would have been easier to contact the baby's Mum and tell her what had happened, and let her make other plans for her child. Instead, you employed someone you'd never met, and then criticised her because she didn't live up to your expectations. You seem to have forgotten that she helped you out at short notice, and was actually doing you a favour.

You should have left the formula out, child locks can be a right pain and she probably didn't want to risk causing damage to your cupboards. Given that you know your place is tricky to locate it seems rather harsh for judging her for struggling to find it.

So you saw her panicked expression, thought she probably wouldn't know how to make up formula, and chose to leave someone else's child with her anyway? A woman you didn't know and had never met and already had doubts about?

Yeah sorry she might be a bit of a doofus but you come off far worse than her.

I would presume so, then these days there's usually instructions with the items and or google too.

We never used child locks so I wouldn't have a clue how to open them

You were in the wrong. I don’t know anyone who would have thrown a babysitter into the deep end like that. Poor preparation, poor guidance, no support. You should have made up the feeds in advance and given very specific instructions about how to warm them, and checked she was comfortable with how to give the feed.

Level 2 quals are GCSE level and are aimed at youngsters who will be working under supervision in a nursery setting. She’s not a nanny and you were expecting far too much of her. She was probably terrified.

Oh lord.

But what do you even mean, “a bit much”?
She got there in time.
She kept baby fed and hydrated despite you locking the formula away.
Presumably you’d mention if you came home to a screaming baby and a soggy nappy?
The L2 childcare course isn’t necessarily that relevant. My mid did one cos she didn’t do well in her GCSEs and had to pick something. She actually worked in a nursery for a short while - but in the preschooler room, no bottles.
You just seem very picky about someone who hasn’t actually done anything wrong.

The only people I've found that can reliably navigate child-proof locks, are children. Anyone beyond 13 quite often has problems.

It isn't obvious as such as lots of houses and not clearly marked so was a little surprising.

If you live in a non obvious place which isn’t clearly marked, why are you so surprised she couldn’t find it?

Why didn’t you just tell the child’s mother that you had a last minute hospital appointment so couldn’t have her child? Did the parents know you were leaving their child with the random babysitter of your work colleague? There’s no way I’d have wanted that to happen to my child!

But, you’re fine, the baby’s fine, you had an emergency sitter, you never have to ask her to do it again. Just let it go.

I don’t really understand the bit about not finding your house. You say it’s hard but then are surprised she struggled? None of which has anything to do with feeding the baby.

I’d be furious as the child’s mother if I found out the godparent left them with someone they didn’t know, had never met. If I were you I’d worry less about her inability to open a child lock and more about your lack of judegement in using random childcare.

YANBU

For goodness sake I'm sure she could've Googled how to open a child locked cupboard.

She sounds fine though… it was 3.5 hours and she used her brain enough to decide that food and water was fine at 7 months to get through instead of disturbing you. You seem very critical.

All this says is that you chose to leave a child (not even your own child!) with someone you didn’t know. So I’m not sure I’d be criticising her.

Could you not have told her your house isn’t clearly marked and is tricky to find, and to give you a call when she was on your road and you’d come out and wave?

I'm 40 and often struggle with child locks that aren't familiar to me. Hope that's ok with you.

You're a bit fucking mean to assume she wouldn't be able to make formula. It comes with instructions plus she is a child carer.

I would have made the formula bottle for her in advance. Her looking flustered because she was late doesn’t make her rubbish.

Nothing on preparing formula milk in the standards:
https://www.gov.uk/government/publications/early-years-practitioner-level-2-qualifications-criteria

I would not assume anyone to be familiar with what is required, and would (if possible) leave the bottle ready-prepared, or very clear instructions. It's also understandable that not everyone has seen every type of childlock, and some are not easy to fathom. Unfortunately it's all too easy to forget they're even there when you're used to them. (I made this type of mistake - I didn't think to show a babysitter how to open the stairgate!) She must have been very embarrassed about not working out how to open the cupboard. Did she try to call you?