First the good news: Even if they get the right to contest it very very rare. I have tried finding examples of this and only found 2 cases where other family members turned up and the Adoptive parents agreed.
We had a contested adoption order. Note at this stage they are applying to be able to contest it not to actually contest it.
In our case the judge decided they could contest it due to a change in circumstance.
It all worked out in the end for us and if they do get the right to contest come back here and I can give you some honest advice.
Right now there is no point in doing much until you find if they will be allowed to contest it. I know its very hard to deal with but this part of the process is not about you and there is no control, its hard and I feel for you.
Look at this as a good thing as you will be able to tell you Little one in the future that there Birth Parents did fight for them and did love them but in the end could not provide the home they needed.
Confirm with the Local Authority that they will tell you as soon as the court it over even if it after 5pm.
We had a few weekend wait while they decided to let us know what was going on and this was not fun.