Yes to Chrysanth, think Cercis is possibly correct too. Prunus laurocerasus is a glossy leathery leaf, it could be this, but there are other possibilities I think.
I thought Cercis, but googling, the leaf venation is wrong. Cercis has the veins all splaying out form the base - see for example: www.jacksonsnurseries.co.uk/cercis-canadensis-hearts-of-gold.html
whereas this specimen has the veins coming off alternately all the way off the midrib.
Whoops - I've just seen she's a toddler, so much that follows is irrelevant, but I'll leave it in case anyone else is interested.
A word on mounting the plants - don't use great swathes of sellotape across the leaf, use tiny strips, as few as possible, eg on across the stalk, and one near the leaf tip if absolutely necessary. See for example:
www.botanicalliaisons.com/new-page
The process of drying and mounting a plant, and labelling it with what it is, where it was found who found it and who confirmed the id, is called "making a voucher specimen".
Beware of plant apps. They're basically just mapping pictures and have no concept of when they've got it wrong. Don't mistake them for botanists - regard them as your completely uninterested in plants BIL flicking through google.
How old is DD3? Can you start encouraging her to take "field notes" - where she saw it, whether it was a bush or a plant, was it carefully planted in a garden or did it look as if it had found its own way there? And if possible, a photograph of it?