Problems with DP ex (again)

[Mrskeats]

I would put this in AIBU but I'm not brave enough :))
For background my DP's ex lives 40 mins away and DP goes over there on a Saturday and a Wednesday evening each week.
Tonight we have had messages from ex-w saying that DP put his daughter (14 in Jan) in danger by letting her walk half a mile to her friends in broad daylight (Saturday lunchtime)
DP had a few errands to run and daughter asked to walk to friends and she knows the way.
Apparently she is telling her solicitor tomorrow!! What she expects them to do is beyond us.
Also she's annoyed he didn't see his son. He's 18 and started a new job on Saturday. Apparently DP should have gone in to the shop to see him. Surely not a good idea on his first training shift.
DP took 3 days off in half term and spent lots of time with them.
He never misses time with them and we are genuinely puzzled by this.
What should he do?

[RandomMess]

Nothing, you both need to ignore her drama!

At 14 what his DD wants will go a huge way, at 18 contact between him and his son is no-one else business! She would get laughed out of court!

[Mrskeats]

Thanks random that's what I thought. I'm sure she is just trying to upset him and won't be phoning anyone. It's just so annoying at times.
I have two kids with my ex and I'm not used to this.

[RandomMess]

Sounds like she tries to control your DP, he just needs to focus on his DC and let her tantrums wash over him!