Car insurance cover for childminder

We have a nanny who minds our children in our house and, from September, will be transporting them to school (in her car).
We asked her to get notification from her insurance company that she is covered to do this.
She had to pay an extra €300 premium, which we will refund to her.
On the new certificate, it states
"Limitations as to Use
Use for social, domestic and pleasure purposes.
Use in connection with the policyholder's and the policyholder's spouse's business plus the carriage of goods and samples (including use by your employees for such purposes), and use for towing (other than for hire or reward) of any one disabled mechanically propelled vehicle or trailer.
The Policy does not cover
Use for hire or reward, racing, pacemaking, speed testing, rallying, reliability trials, commercial travelling and in connection with any trade or business. Use for any purpose in connection with the motor trade. "

Two things concern me:
a) it only states carriage of goods and samples (i.e., not people)
b) While it states that it covers use in connection with the policyholders business, under the "policy does not cover" section, it states that it does not cover "........in connection with any trade or business".

I rang the broker who set it up, and she said that carriage of goods is standard language and that it does cover people, but the insurer (Liberty) will never write that.
Is that correct? Seems strange to me.
Regarding (b) above, she said that the trade or business referred to is related to pacemaking etc. That is not clear to me from the language here.
Can anybody clarify if that means that she is covered to carry our kids or not?

Separately, we have a letter from Liberty saying that we are indemnified in respect of liability which may be attached to us as a result of negligence by the driver.

So that seems to cover us from a claim against us, but is she covered in case something happens our kids while she is driving them?