Firstly, you'll never get to understand the character. Just give up. It'll save your time. 😛
Now, Just forget about her marriage and love.
Think of the 2 and a half years, when she was in love with Armaan. The LOVE , all the members are talking about. The LOVE for which she cried in every episode.
1. Where was that Love, when she used to say harsh things to Armaan and then he used to leave Sanjeevni forever (and then come back again later😛). Every other month they used to make him run away and then Ridhhima used to REALISE his LOVE for her. This used to happen every other or alternate month. She never leant from her mistakes.
2. She was never sure of her relationship with Armaan. When she first confessed, she asked him to hide it from everyone, coz she wasn't sure. Then when Sanjeevni was in crisis, she contemplated for weeks to let Armaan know about it. Which meant she dint trusted him. Then when they were about to get married, she wasn't even sure at that time. GOD!!! The girl is highly confused or Dumb should I say. Why to waste 2.5 years when she's not sure?
3. Now comes the most important part. Who told her to shout 'RAPE RAPE' in the hospital in front of the whole staff. No sane girl do that. Only girls or aunties in Ekta's Show go n shout things in parties and weddings and public places. The girl never used her brain. She reacts b4 giving a thought to the situation. Wonder how she's the best intern??? The whole Marriage thing was cz of her stupid act.
4. Now when the wedding happened, and Armaan was nowhere in scene. AND she started to develop feelings for SID. I supported her that even she has the right to forget her past and move on. Coz only we and CV's knew by the ads/promos/IF that Armaan will come back. Ridhhima-the-Character dint knew about it. For her Armaan was never to come back and Sid is her future. She's MARRIED to him. Thats the end to it.
5. Now comes your questions about why dint she asked him about his illness. Well, thats what the character is about. Dumb and confused. But on the other hand even Armaan dint asked anyone that how is Ridhhima Alive? When she was supposed to be dead.
But then ..Thats DMG for you. Full of CRAP!!!!!!!!