Was Gautama Buddha's wife Yesodhara in any way instrumental in Him becoming a Buddha? Considering the story we know about the life of Buddha as Siddhartha and also considering that Yesodhara was Buddha's partner in His many previous lives, can we say that Yesodhara was somehow instrumental in Siddhartha becoming a Buddha? 

OR

With or without Her being in His life He would have made it? 

(Her pervious life with Buddha is in wiki article and here.)

I know this question is as such irrelevant to practice but I am trying to get around this idea called 'soul-mates' which is in pop-media.
I am trying to get around this idea called 'soul-mates' which is in pop-media.

The term 'soul-mates' doesn't make sense in ultimate reality as there are no souls to begin with. But if you simply interpret it as being the perfect husband and wife, it has meaning in Buddhism.

With or without Her being in His life He would have made it?

Once the Buddha Deepankara gave the prediction that the Bodhisatta is going to be a Buddha, it was going to happen one way or the other.
Yashodara Theri herself answers this question in her last words before she passed away.
“me saranam atthano” (“I am my own refuge”). 

Nevertheless, she was the perfect wife to the Bodhisatta. 


  The relationship between Yashodhara and Prince Siddhartha was long and
  deep-rooted. It had started many, many years ago at the time of the
  Dîpankara Buddha. At that time, the Prince (Bodhisatta) was born as an
  ascetic by the name of Sumedha. After an exceedingly long period of
  practicing the ten virtues, the Bodhisatta Sumedha had finally
  completed the eight requirements to receive the definite proclamation
  of Buddhahood from the Dîpankara Buddha. Yashodhara, at that time, was
  born as a noble lady by the name of Sumitta. She saw the Buddha
  Dîpankara give the Bodhisattva eight handfuls of white jasmine flowers
  and the definite proclamation that He would be a Buddha by the name of
  Gotama, of the Sakyan caste, in the distant future. Cutting off her
  hair, she aspired to be His consort and helpmate and to support Him
  actively in His quest for Buddhahood.


Since then she had been the wife of no other but him during the entire period(100,000 world cycles and four infinite periods).

Another example for a perfect couple is Nakula matha and Nakula pitha.