Controller described witnessing a loss of separation event between two arrival aircraft; the reporter noting several suggested remedies were provided to the Controller but none were implemented.

Narrative

I was asked to be a coordinator for the RADAR Controller by the CIC at the time. When I sat down; I quickly noticed the Controller was already well behind and struggling to keep up with the traffic. The B737 was cleared for the ILS approach to Runway 16L and joined the localizer at about at 15 NM final at 3;000 FT. The BE30 was also landing and was coming inbound from the south east level at 3;000 FT. The BE30 was on a vector towards the localizer at about an 11 NM Final. When the BE30 checked onto our frequency; I advised the RADAR Controller of the potential conflict. There was no immediate action taken by the Controller. I then went on to coordinate with another sector in our area trying to locate a NORDO military aircraft. When I looked back at the developing conflict; the two aircraft were converging at the same altitude; but still approximately 7 miles apart. I then advised the RADAR Controller to turn the BE30. Again; the Controller did not take any immediate action. Then the Controller turned the BE30 to a heading of 360; and I advised them that heading was not going to work; they then turned the BE30 to a heading of 040. The BE30 was indicating approximately 200 KTS over the ground; thus unable to make a very tight turn. While in the turn; the BE30 and the B737 were converging at the same altitude and passed each other about 2 miles apart. There was no TCAS or RA reported by either pilot. Recommendation; I'm not sure what else I; as a coordinator at the time; could have done other than key up the frequency myself to turn the BE30. Unfortunately we do not have that capability at our facility from the coordinator position.