This is a rumor of how to get it.
She probly won't give it to you because you need to have shaymin in your party. Then she will give it to you.
I don't think any particular slot in your party, just go to Floaroma Town and talk to the lady next to the flower shop in order to obtain the Gracidia Flower. Hope this helps :)
You can obtain the gracidea flower in one condition. You have to transfer the Shaymin from the Nintendo Event or from Oak's Letter via Mystery Gift in Pokemon Platinum. So first have the Shaymin in either Platinum, HG or SS and transfer it to your White game. PS. You needed 2 DS to transfer.
Sorry. You cannot obtain Lugia in Platinum. You have to trade it from HGSS.
Get the best pokeballs and go search for it.
You have to have Pokemon ranger. If you do complete a special mission, and then obtain the egg, then you put platinum in a different ds, and connect them
as far as i know its not possible to obtain a "wild" groudon on Pokemon platinum. however you can trade it in from other games such as Pokemon soul silver.
migrate from fire red
only throgh the pal; park
Yes, you are able to obtain Shaymin.
You cannot get the gracedia flower in Pokemon pearl. Rather, you must obtain Pokemon platinum and trade your shaymin there. You talk to a lady on the road in Floaroma town and she will give you the flower. Hope this helps.
You cannot obtain Unova Pokemon in Platinum. But, if you know how to code, it is possible to add Black and White Pokemon into your PokeDex, as well as X and Y.