In general, studios invite actresses to perform. Often times agencies will "work" a model with various studios, to get the actress roles. Sometimes this ether doesn't happen or is not an efficient process. Here's where fans of actresses, such as Danielle, can help by imploring various studios to shoot her, via Twitter.
Hey, dezertimagez, glad to see you de-lurk! Your work is always top-notch, both technically and in the style and beauty of the models and settings you use. I hope you post more often with more info on your shootings! (And do more with our favorites here, like Danielle and Katy Ann...)
Back OT, I find it odd that someone so experienced, dedicated, diverse, well-known, and indeed so avidly sought by fans such as Danielle needs any more promotion to get new material produced. I know studios always look for "fresh meat" (SIC, LOL), but in Danielle's case you would think they could expect to depend on solid response and revenue. Maybe that's just the opinion of a TPB member, but, dunno, seems like Danielle should be enshrined in some AVN museum by now. Or is that (and her age) a factor?