After seeing the CB till now I am just thinking what exactly Radhika is.
In context of the Krishn Avtaar katha of Lord Vishnu, Radhika can be seen as a combination of Radha, Meera and Rukmini.
1. Radha
As all know that Radha and Krishn are eternal lovers. They are like Do Shareer Ek Praan. Srimati Radharani is the direct counterpart of Lord Krishna. Without Radha Rani there is no meaning to loard Krishna and without Krishna there is no meaning to Radha Rani.
That is why we have their Ardh Nareshwar swaroop which teaches us being in Love is like to complete others life with what all we have by giving everything which was "Mine" and now "Ours".
Radhika is always cosidered as a thing,which was used for the sake of happiness and respect of Shastri ji and family. And Dev loves Radhika from the bottom of his heart. He wants to give all the happiness, respect and rights(Adhikar and Anumati) and make her life complete. As she did not have all these things in her life till now.
2. Meera
Meera considered Krishn as her husband and did all the rituals as a wife.
Radhika also did all the:
Vrats like Vat Savitri, Hariyali Amavasya.
Rituals like Purohit puja alongwith Dev and many more.
Saved Dev's life by applying Vibhuti on his forehead.
Radhika can bear all the difficulties, as a wife, for the sake of Dev's happiness...remember the question that Kanha asked her in the 24/08 epi.."kya tum dev ke sukh ke khatir har dukh utaa sakti ho?." She was ready as always but now she admitted.
So she is also the meera of Dev's life and can do anything for him but unlike Meera she do not want to disclose the truth that she is the wedded wife of Dev. Just want to complete her duties as wife and be remained hidden from the world as she knew ki wo duniya ki nazar me Dev ki Byahta nahi hai (she is not wedded to Dev).
3. Rukmini
And if most awaited RaDev marriage will be happened without any twists then Radhika will become the Rukmini also. Rukmini was the Avtaar of Mata Laxmi is the principal wife and queen of Bhagwaan Vishnu's Krishnavtar.
After the marriage she need not to hide her Love and Concerns for Dev as whole world will be knowing the truth and can not doubt their relationship. Their marriage will have the blessings from from their family members(and also our Pushp Varsha....).
Now their Love will have the name also in the Dev's word "Main apne pyaar ko ek naam dena chahta hun".
So Radhika is truly the telly incarnation of Radha, Meera and Rukmini for the television avtaar of Lord Krishna(Dev). And Radhika's persona has all the three most important aspects of Krishna Leela.
I am not very good at putting thoughts into words. But tried hard to give this post a readable view.
Let me know if any mistakes so that i can improve myself.