Is this the same estate about which you posted previously?
http://www.askaboutmoney.com/showthread.php?p=325157#post325157
Was there previously an agreement of some sort that there would be a deed of family arrangment (as suggested in previous posts)? This is the sort of situation where you need detailed, case-specific advice.
I would not necessarily say that the solicitor is obliged to "manage the situation" or to "give direction". Certainly, the solicitor should be able to advise you (or more properly the administrators), in writing, as to:
A. The options open to you to advance matters and
B. Whether this requires that the warring administrators require separate independent legal advice (it seems very likely that they do).
Ask for this advice. If you don't get it, go to another solicitor. However, in general where there are two administrators appointed, then nothing can be done except by their agreement or -in the absence of agreement - by court order. If you can find a consensus without litigation, it will certainly be cheaper.