I recently game across this. A family wanted one child to be paid on one card and the other child on another. I had to create two different family accounts as a work around. They then complained that they received all email blast twice. I have only come across this once. The only other option is for the families to go on the parent portal and select 'make a payment' and pay half on separate cards.

I have had this happen also.  A bigger issue is when I have a divorced family where both families are responsible for the balance but there is only one login available.  They don't talk to each other let alone want the other to know a password to get into the account to make a payment.  It would be nice if there was the ability to have multiple logins for a family.

We've only been in business a year and a half, and it was amazing to me that divorced families make it my problem.  I have the same issue as you both describe above.  I take divorced families off autopay, add the second email address to their account separated by a comma, (that way both emails get the statements) they send in two different checks.  Painful.  Then half the time one of them doesn't pay.  Adding a second auto pay card or NACHA info would be great.  Maybe they could do this request with the other one that I wrote up to let you specify an autopay date by family...

Yes, We have this problem too.  Two credit cards would be great.  We also have to hand run these "split" accounts.