What can we do?

One trunk is about 7′, the second about 9′ and the third 12′ in a fairly but not totally sunny, west-facing room with huge windows.  The bamboo stakes have long since failed to keep these abundantly leaved FLF standing upright.  This/these plant(s) is about 13 years old.  Occasionally, a leaf falls but the plant is healthy with over 100 leaves.

How do we support it so that it either relies upon the support to be upright (the bamboo stakes and the stems lean at about.30 degrees from perpendicular with the 12′ stem tied to an upstairs bannister to prevent the trio of stems from tilting any further.  We have 18-20′ ceiling  – so there is plenty of room above.  The FLF is located in the corner of the room – so affixing a central pole to the neighboring walls is conceivable…but is this the best thing for the plant?

Help…please!  Thank you immensely