Spider with Spiderlings

A blistery day at Rye so decided to do a bit of Beach Combing and when we looked at this shell still connected to its other half we thought, it turned out it was connected by this lady's web. Baby spiders started to run but stayed close to mum instead.
She wouldn't move and we didn't want to disturb her and the young any more than we already had. We took these then put the other shell back and nestled it into the shingle.

Thanks to Jones J E for an ID on these spiders of Drassodes sp.