I'd do benefit of the doubt this time - but keep watch on the atmosphere.
Her defensiveness (& slamming down the phone) is much more worrying sign than the talking - talking on the phone while looking after a baby isn't automatically bad - she could have been making plans to meet up with other nannies & their charges, which is a good thing (unless you don't want her to do that ...?) Was she going against your explicit instructions not to chat on the phone, though?
Little things can be reliable alarm bells, though: we sacked a nanny after two days after a string of little things: she was an hour late her first day, she "forgot" her swimming kit on a day we'd arranged she'd take ds to the pool; etc.; but the clincher was dh coming home to a silent house & after several minutes coming into the living room to find ds (aged 13 months) sitting by himself at one end of the living room while she read a mag at the other. It was that non-interaction that made us sure she was wrong for us. And we definitely did the right thing by parting company with her.
I thin you are right to be a bit annoyed. And I think her defensive behaviour says it all really.
However, I don't actually mind if my nanny yaks on the phone noe and then. It could be her phone rang, she picked it up and had a chat with a friend for 5 minutes. If I was home looking after the kids, I would do this so why not nanny. I'm a bit concerned however that the baby was in the "cage" which I assume is a play pen or travel cot.
Have you got a nanny diary? (I should get for commission for recommending nanny diares so often).
My son turned 1 two weeks ago. He's a very good tempered child and very inquisitive, always exploring the room / things in it, which I am happy for him to do. Its tiring work which is why I have her here 1 day per week.
Its her 2nd day alone with him. They went to a baby group this morning I don't think she was making any arrangements regarding his activities...
I am really tired and think this is colouring my being upset. I'll think on it again tomorrow.
Yes, sorry I refer to the playpen as a "cage" cos that's what it looks like, and I've sat in it myself and it feels like one...
I hate it when my mobile rings, it is next to impossible to answer a voice call with baby, 2 year old and 4 year old around. Text messages are far better - often arrange meetups with other childcarers via text message, as we all find it hard to answer a voice call - but can answer a text when the children are safety occupied.
I don't think you are over reacting to the situation you walked into... though probably best not to take any action at this stage, just make a note of it for future reference (such as for the end of week 1/week 2 review).