I doubt the mare has true Roan as her head is not solid- I think she has Varnish, which is what is causing the roaining......or if you know for sure she is not Varnish I would suggest Sabino (unless of course she is going Grey!)
The foal definitely has Sabino and as it is a colt (and very cute too) you need to test for LWO- there is no point even making a guess about it, if it is in the works it needs to be tested!