I heard that the big females will hold off the bank in deeper water. I also heard that the big ones will spawn in top of trees in deep water. Have any of you guys had any luck with this?

Females should not be far off from where the males are stationed. Look for the nearest quick drop in water depth, channel edge, or submerged cover, that's closest to the spot where the males are gathered. The females should be staging there, and making runs into the shallow water to feed, at various times during the day.

Northernmost banks/creeks will warm first, as they get greater amounts of sunlight time, regardless of which part of the lake they're located.

As Crappie migrate into their spawning areas, they'll follow the channels or channel edges. Until time to actually spawn, they're on the feed ... and both males and females will move in and out of shallow water, following their food source. Once on the bed, they won't actively feed ... but, they will attack anything perceived as a threat to the eggs/fry. Cold fronts and water level fluctuation will reposition the fish, but they'll go right back to their routine, as soon as temps rise & water levels stabilize (if it is not huge big rize).

Crappie will also follow slow rising water, right up into the flooded brush/weeds/trees, because food is readily available there and easy to find.

Some of the females can and do spawn in the top of trees if conditions are correct for them.

Mud-Dabber

I'm a firm believer that lots of big fish spawn in deep water.
The best stringers Paul and I have caught during tournaments, were during the spring were when fish were on the banks but we were fishing 15-30' deep timber.
16.24# on 7 fish at millwood
15.42# on 7 fish at LOP
14.75# on 7 fish at LOP

We've had another 16# and two 15# days on Millwodd fishing deep timber during the spawn.

You pull off the bank where you find males and fish the deeper water and you'll catch better quality.

Sounds good, I will give it a try.