The following stood out for me, though may have been a misreading of the little information the OP has been able to give:
The OP's daughter has no friends her own age.
She relies heavily on her parents for emotional support and security.
She has no clear life plan other than to become a mother - which is a fine ambition, but she had no scaffolding for the emotional and financial support underpinning her own household and independent life in place (e.g. stable partner, circle of friends, somewhere of her own to live, plan for providing for the child long-term).
The first pregnancy was unplanned, but she made a positive choice to continue it, which isn't typical at her age.
The boyfriend doesn't seem a very significant figure in all this, and she doesn't seem to see him as her partner and main emotional or practical support.
She lives in a village rather than a city, where there are fewer employment, further education and social opportunities - and might find it harder to meet new people, new friends her own age, or future partners if she becomes single again. Most young people leave and move to cities for work and to meet people - growing up by learning to get on with people who are very different in houseshares etc even if they don't go to college.
Does she even drive?
The decision not to go to college has somehow masked the decision not to leave the nest, exacerbated by the pandemic perhaps.
All in all a very, very young 19.
It isn't clear that she has any life skills, and would be capable of finding somewhere to live, managing utilities/the food shop, self-care, managing finances, even before a baby arrives.
The DD didn't sound keen for anything to change other than for it to be better - her current teenage life being looked after, with a baby added.
If I were the OP I would be less worried about dealing with the nappies but this set-up continuing into the long-term. Buying a flat sounds a good idea & extraordinarily generous - she is a fortunate young woman in that regard - but she will need support to get established beyond that too. She need to learn how to look after herself, entertain herself, find her place in the community, very quickly too, without ringing her parents several times a day.
A lot of this is about failure to launch. The critics on the thread point out that it's reasonable to not go to college, reasonable to want another baby after a loss, reasonable to want moral and financial support from your own comfortable and loving parents when you are only 19, reasonable to work 0.8FTE in a keyworker job.
Yes, but taken as a package it's not a move towards independence - she needs some firm support to help her find her own two feet and flourish.