@Ivotas:
1. As Cap´n Carter pointed it out whatever body part creates is still something that needs to grow out of a solid place. Her power is the "hana hana" power after all which means the growing part is pretty much indicated within the name itself.
If Blueno can cut a door in air to another dimension, Robin can have her limbs grow out of anything, including air or water molecules. The only way around this unrestricted domain would be that she needs to be touching the person to make her flowers sproud; theoretically, this would imply she's growing hands under her feet which then borrow through the ground up to who she's trying to attack.
@Ivotas:
2. So far whenever Robin has used her power she for herself had control over the body parts. In other words, no matter what she let grew it was still her one and only brain that was controling everything. We´ve never seen her create something that has a free will of it´s own so a clone couldn´t get created because it would have zero own will and would completely obey to Robins thoughts.
Oda hasn't specified what Robin can/cannot sprout, but thus far she's been able to produce limbs and organs. Now, we've yet to see any internal organs and it very well be that Robin can't sproud a new heart if she gets stabbed through, but I'm going to wager that if she could sprout eyes she could very well sprout other organs as well; as such, she could create a brain, but that does not imply she could create a mind. Possibly (and at best), the clone would be semi-autonomous, but more likely it would be under total control of Robin.
But then again, it's just like I said; what's the point except for reconnoissance? Robin doesn't even really need a clone to protect herself since she's already a battle-hardened Paramecia.