First a disclaimer that I am NOT and advocate and in this case am not fully familiar with all the applicable law. I am however fully aware of Res Judicata and its more powerful elder brother constructive Res Judicata which most advocates fail to raise when raising the defense of Res Judicata, Check the section numbers under CPC.
If assuming that res judicata or double jeopardy is applicable, you need to argue that whatever is argued now, could have been argued earlier but was not argued and is therefore waived (constructive res judicata. Plain res judicata does not cover this and the Judge is not going to be your advocate). The doctrine of waiver also kicks in and so does the theory of estoppel. You need to club all of them together and reference them just to be sure that you have not missed anything that fundamentally precludes re-litigation. That said, new circumstances always form a basis for a new maintenance application.
125 Cr.P.C. is a wild beast. It is the most powerful of all the weapons in the maintenance laws. Other maintenance laws are covered much better (from a man's perspective of course) under the law of limitations, for example. 125 Cr.P.C. is not. For example, maintenance cannot be waived pursuant to 125 Cr.P.C. but can be argued to be waived in civil proceedings, if not timely raised or if raised after many years (limitation Act).
As a general rule, Civil Proceedings against you, ruled in your favour, can be used to argue against Criminal proceedings filed against you, but not the other way around (Please confirm this statement). The logic is that the standard of proof in a criminal proceeding against you is higher than in a civil proceeding.
If there are two parallel proceedings... one in a civil court and another in a criminal court based upon the same factual allegations, then it is always better, if either one is ruled in your favor, to let the other party go for an appeal and lose. Why? If the High Court affirms the judgement, then the FACTUAL FINDINGS of the trial Court in that judgement, civil or criminal, are now cast in stone and all the lower courts, whether civil or criminal, are bound by these factual findings affirmed by the High Court, even if the Acts under which new proceedings are filed or currently ongoing, whether civil or criminal, are different. Of course, you need good legal skills to argue this. It is not merely a direct application of double jeopardy or res judicata but derived from the same concept. If the proceeding under which you prevailed (for e.g. in Family Court) was not appealed, you ought to argue that as it was not appealed, it has the same weight as that of a High Court Order. Frankly, this is a far-fetched argument but hey, why not?
I am not an advocate so even if my above statements turn out to be inaccurate, I hope that they provide some hints on possibilities you should explore!