I'd let her call. For one thing if the custodial agreement specifically states unlimited phone access then she could take you to court for contempt on that one. But also to this day I know that if I wake up at 3 am from a bad dream and feel compelled to call my mom, she will welcome that call - and I turned 40 this year!
So we're OK there. (That and I can't imagine a family court judge actually entertaining a contempt motion for a 3 a.m. tantrum. There's a mandatory mediation clause in just about every custody plan in WI, so that's where it would end up.)
I'm still wondering, though...the request to call Mom, at the time, didn't seem like a particularly coherent request. It was delivered a single time, sandwiched between all the other demands and moans. Why does that request get elevated? If we'd called, Mom wouldn't have answered (as we found out)... and SD would have probably woken up for much longer, freaked out that we couldn't reach Mom, and Mom probably would have complained that we're incapable of soothing a simple nightmare.
To be sure, we'll be calling each and every time there is a request now, until we're told otherwise. Which, if history dictates, will be right after the next time there is a middle-of-the-night call.
I'm 34 and I think my mom would freak if I called her at 3 a.m., but that's just how my family is. Between about 10 pm and 8 am, unexpected phone calls are either because someone has died or someone is dying.
Sigh....I think I'm just getting tired of feeling like we have to anticipate and work around SD's mom's random freakouts (because everyone who chimed in about the freakout seems to agree that SD's mom's voice mail screed was out of line). That seems to be the bigger issue here, really. We're gearing up to TTC and I'm shuddering to think what's going to happen if/when we actually do have a child together. Will I end up parenting my child according to how it'll get back to my SD's mom?
Ugh. I think I need to go to bed and stop obsessing.