If she is not used to public transport AND she has to change at Birmingham New Street
The OP has repeatedly said she wouldn't have to.
But since Mordor Central Birmingham New St is used heavily by pupils who commute to and from the Birmingham grammar and private schools by train, I think the idea that it's a dark maw into which children disappear never to emerge can be a little overplayed.
14 year old child found wandering at train station
As well as the permanently manned information desks by the barriers, and the permanent presence both at concourse and platform level of Network Rail, Virgin and London Midland staff, there are shops and cafes open 0630 to Christ Knows When, and there's usually a BTP presence. It's hard to see how you could end up "wandering". Find someone in uniform. Sorted. Failing that, go into a shop. Sorted. If you can walk 50 yards at New St without passing someone in uniform, especially with all the extra staff on duty to deal with issues arising from the rebuilding work, I'd be amazed. The Stephenson St entrance is now closed so it's not possible to accidentally go out of the "back", either. It's also very rare for a long-distance train not to have TOC staff on the platform to deal with passengers, and increasingly there are dispatch staff on platforms even for the suburban stuff.
I would worry about my child changing trains on some godforsaken station in the middle of nowhere, served by two trains hourly and only manned in the peaks. But New St? Depending on your measure it's the busiest station in the country (it certainly is in terms of train movements) and it's staffed appropriately. It's got many failings, but a shortage of staff (and, in my experience, helpful staff) isn't one of them.