I really agree with this.
OP, you sound like such a nice women so I will try and be temperate in my response 😁.
I have children around this age.
This is a bloody disaster.
She has health issues, no A levels as a result, a 5 minute relationship and has now decided to play mummy.
She is 100% unrealistic and is signing her future away, all on the back of you and your husband.
Her health issues mean you have already had a lot of worry, and now, with no job, education, no prospects, she has decided to have a baby.
The luxury of knowing the dirty business of it will be paid for by her parents.
The relationship is highly unlikely to last.
Why?
Because they are young and barely know each other.
Your other child has most likely lived in the shadow of her sisters health issues, and now will have a crying baby and everything that involves, in her home as she trys to do her exams.
Not right.
Not fair.
You need to give some long hard thought to this.
I do not think your daughter gets to decide that she can stay at home and put this on you.
Your DD2 has every right to expect her exam year to be a top priority in her home.
You are utterly failing her, and her future by not being very cognisant of that.
Your daughter is consumed by herself and her wants, but you should not be.
You have two daughters.
You need to look at them both.
If your daughter feels she does not meet her exam potential because of this upheaval, she will have every right to blame you, her parents, for not stepping in and doing the right thing for her during a very stressful, critical to her future, exam year.
I really wish you the best.