OP putting aside if nursery full-time is good or bad for a child
I have just had a look at the nurseries near me (as many years since I needed one)
1 opens at 6:30am
The Hospital One opens at 6:45am
most open at 7
2 doesn't open until 8 am.
most are open until 6-7 pm
Not one of them is open on a Saturday or Sunday (including the Hospital one)
I live in a fairly large town in the SE. I checked 25 nurseries
You need to work out how you will go about this.
A nursery will not be the answer you need.
Could you get an aupair in whom can have your dd for 1 hour in the morning and take them to nursery then have them on Saturdays?
Or a uni student if you live near a university?
A weekend childminder?
You say family is a possibility will they support similar?
You can argue that this should happen and it is possible, however, unless you can find one that does this you need to find a solution for your current issue.
If you and your husband working split shifts/opposite weekends isn't a possibility you have to work out what is a possibility.