Feeling sad

Hi there , first post here, I have one granddaughter and she has lived with me for her entire life so far, she's 14 months, she's my sons and his partner.
We have an incredible bond and I absolutely adore her and she loves me back ❤️ I've helped raise her and it's the best thing in the world being her nanny .
They're moving out in 2 weeks and I feel crushed, I'm slowly coming to terms with it and they're only going half an hour away but the thought of not seeing her every day is awful and the reality of it all is hitting hard .
I get on well with my son and partner although things have been and can be strained with mum at times but thats a whole other story.
I'm just venting really, I just know how much I'm going to miss her and I know I will still see her it's just a bit heartbreaking. I think I've become a bit too attached sometimes and she's very attached to me too, often favouring me over her parents . I still have my daughter here which is great as we are close . It's partly fear too that I won't be seeing her much.
I know I've been incredibly lucky to have been a big part of her life so far, it's going to be a hard transition and I know I'll adapt .
Thanks for reading my rambling if you got this far