A few observations ;
Absence of insurance is a strict liability type of offence.
The fact of absence of insurance creates an automatic assumption of guilt.
It is possible to avoid conviction for no insurance if there is a persuasively compelling reason.
Unhappily, failure to renew through oversight is probably not within the scope of a valid defence.
The other matters should help to mitigate as clearly this was a "sin" of omission rather than commission.
Give the judge as much evidence as is possible to allow them to mitigate the severity of penalty.
As far as the Gardaí are concerned there is virtually no true discretion about bringing a charge as the absence of insurance is treated seriously.
You could only object to a prosecution if a letter of comfort had issued indicating that there would be no action and a summons then issued.
Court attendance is imperative
People have adverted to the issue of disclosure for the new insurance. Two points occur to me ;
1. What is required depends on the exact wording of the proposal form or on the presumptions made if seeking a quote on line or over the telephone.
It is possible that OP's ex. may have been entirely within her rights not to say anything about a pending prosecution when proposing for the new insurance. When does a pending prosecution actually become a pending prosecution ? If there was no pending prosecution the morning after the traffic stop would she have to have declared the matter to the new insurers ? Arguably not.
This is a strict or narrow construction of the issue.
2. Insurance contracts are written on an utmost good faith basis alias uberrima fides.
This concept includes the obligation to disclose material facts.
A material fact is one that is capable of influencing a prudent insurance underwriter in deciding whether or not to accept a risk proposed for insurance and, if so, upon what terms and conditions.
It is for the insurance underwriter to decide if a fact is material not the party proposing or renewing.
If there is doubt the general rule is to disclose thus keeping you on the right side of right.
I would argue that the proposer [the ex.] may well have failed in the duty of disclosure in not revealing the traffic stop by Gardai because the likely consequences of that event could be reasonably expected to be known.
However, the new insurers, on hearing of the full circumstances, might take a lenient view.
If there is a conviction for no insurance that will indisputably have to be disclosed before next renewal.
If insurers decide to cancel the new insurance ab initio [from the beginning] that of itself then becomes a material fact to be disclosed in any future applications for insurance and adds additional grief to the situation.
The very best outcome here is a relatively lenient penalty based upon persuasive mitigation and a kindly disposed insurance underwriter to decide to continue the new insurance contract as if it had been validly formed.