I think it is best for people to appoint solicitor - people who are already upset do not have the knowledge to sort all this out (I am not a lawyer or work for one)
What complete rubbish - many bereaved people have the knowledge to administer estates, despite also being 'upset', I did my mums.
Op, how old is your DS, what is the likelihood of you both dying before he turns say 21? Could you maybe add a trusted friend as a joint executor, or one of DH parents (how old are you/they?)
We changed our wills 3yrs ago, putting SIL as sole executor, to be joined at 18 by each DC. DS is now 20, DD almost 18, whilst I wouldn't necessarily want either of them alone, I think joint with another adult (two in our case) is fine.
If you do go with DS as sole executor at 18, then maybe make a detailed list of what assets you have, where house deeds are etc to make life easier.
We put 23 as the age to attain, but I think 25 would be better. But then you need to sort out a trustee for the estate too.