I'm saying YABU @Andiey because your DSD has her own life, friends, job near Uni, and social circle. My DC when they were at Uni, knew a few people there who went home 2 or 3 weekends a month, and every minute of every holiday, because they didn't like being away from their parents. They seemed really needy and still quite childish. A young adult 'child' who wants to stay around Uni in the holidays, and maybe travel a bit, and doesn't go home very often is far more independent and mature IMO, and will handle adult life better.
Unsurprisingly, the ones who kept going home, are still living with their parents at nearly 30, and the ones who didn't go home very often - like my DC, left home and had their own place by 22-23, and never returned home. I'm not having a go at people who are still living with parents at 30, and I know it's unavoidable sometimes, but there is definitely a pattern. The more clingy 'I need my mum' ones who went home all the time, never left home. And the ones who returned home fairly infrequently moved into their own place as soon as they could.
When my 2 went to Uni, they were there at the same time, as one had a gap year - there's just over a year between them, and when they both left for Uni at the same time, the feeling of emptiness and sadness was palpable. I missed them so much, that my heart ached. They did come home for a few days in early November though, and for Christmas - 2 weeks, (the first year at Uni,) and I have to say I would have been crushed if they'd not come home at Christmas. (I wouldn't have complained or let them know I was bothered though.)
Then they came at Easter for a few days, then shot back to Uni. For the summer, they came home for 2 weeks, and spent the rest of the 7-8 weeks, travelling, going to festivals, and staying at various friends houses. (Also doing casual work for some extra money.) They did spend every Christmas 'at home' though. They both got their own place by 22-23 and never returned home. They live 20 and 30 minutes drive away, so not too far away! 
So all you can do is let your DSD live her life, and just bottle your feelings. Just rant on here about it, many Mumsnetters are good listeners. 😍
YANBU to be a bit sad about it though. And I hope you have a lovely Christmas anyway. You can always facetime your DSD on WhatsApp. 