Pooled acct in Partic-directed plan

Plan used to be hubby & wife pooled account.

Then daughter joined the company in 2016. 

Plan was amended to participant-directed effective 1/1/16.  Daughter opened her own account.

However, the husband and wife contributed to utilize the pooled accounts (there were two, now there's three!).

What kind of problems am I looking at with the pooled account for the parents, but an individual account for the daughter?

(No other employees)

The plan probably has, or should have, language that says what happens if participants don't give instructions to self-direct.  So not necessarily any problems.

Can a case be made that one of the choices is to stay in the pooled part of the plan? 

That seems to be the choice they made in effect after all.