Marie also made pace with the Habsburgs who Henry IV planned to go to war with before his assassination. This was very important as France could not really afford to go to war. Marie also brought peace and security to France by marrying her son, Louis to a Spanish princess called Anne, and her daughter Elizabeth to the heir to the Spain, Philip IV. These marriages were dealt with in the Treaty of Fontainebleau in 1612, the treaty and Marie’s actions brought peace between Spain and France for ten years.
When at the 1614 Estates General, Marie saw a young man called Richelieu; he was an outstanding source of information and gave Marie advice on how to handle situations. She then gave him a small post in the royal council. Without Richelieu it is probable that Marie would have seen many more revolts and rebellions against her, not only this but Richelieu brought a further sense of security to the country. Marie's managerial skills were shown again during conflict between the pope and the French clergy. This could have caused civil war and so prevented possible revolution.
Another way in which Marie d’Medici was effective was in keeping the nobility quiet; doing this meant a smaller chance of revolutions and the kept peasants and lower classes quiet in turn. However, the way she kept the nobles quiet made her ineffective, and this brings us to the second half of the argument. By bribing the nobles she showed weakness and that she couldn’t make them happy by laws and actions and this could have lead to a revolt.
Calling the Estates general or états généraux was a sign of weakness for any monarch and so was called very infrequently. Marie called one in 1614 and this made public confidence in the crown very low and so held back the development of France.
An obvious show of ineffectiveness was the revolt of 1614 let by Condé; he was able to collect a large number of supporters and even some Huguenots supported him. However Marie did help the King reconcile with Condé and realised that his actions weren’t to rid the King but to get some minor power.
Another one of Marie's flaws was that she had a tendency to choose favourites, such as Concini. This may have let to some bad decisions by choosing a favourite person and not the best idea.
I believe that Marie was quite effective but she only needed to be more confident in herself, not relying on favourites and not calling the 1614 états généraux.