White flowering cherry

Hello everybody!
My daughter presented me with a gorgeous flowering cherry from M & S for Mother's Day. It started flowering very soon with small white flowers and now there are already small green leaves. It is about 55 cm tall from the surface. I am not sure what to do with it now when it will soon stop flowering.
It looks similar to Prunus incisa 'Paean' but with white flowers. Could anybody help me please to identify this flowering cherry?
Thank you in advance.

 

Hi, @Black Orchid what a lovely keepsake gift although I can't help with the ID sorry ...i did goggle M&S Cherry Blossom tree and read a review dated March 2018 and I quote

I suppose you could email M&S and ask for further information to be sure that It is the same CB Tree..... they also mention when ordering that the colours available will vary so maybe this is the same Cherry Tree as yours ... IMHO I think that I would just find a suitable spot in your garden to plant it and enjoy

 

Thank you for your info and desire to help. The main reason why I want to know more about this cherry tree I just want to know if it is hardy enough to be planted in a big pot in Manchester area.
Unfortunately when my Bird of Paradise became too big for my hall I planted it in a bigger pot in my garden last spring and it didn't survive the winter. It made me very upset.
Another reason for me to know the cherry name is to understand how big it can grow. I am very greedy with buying more and more plants both for my house and the garden and I am afraid there will be no space to move in the nearest future. But when they grow well and flower it is a great pleasure.
My first dwarf rhododendron is in blossom now. See the attached picture.