TRACON Controller reported they misjudged the rate of turn when vectoring an aircraft to the final approach course resulting in the aircraft crossing the final approach course and flying below the Minimum Vectoring Altitude.

Narrative

Aircraft X had previously been taken off of the ZZZZZ descend via STAR due to traffic. I left them on the lateral path of the STAR; but assigned altitudes. They were being vectored for an ILS approach to Runway XXL I issued Aircraft X a slight heading of 180 as a lead in to the base turn and a descent to 10000 ft. Several miles later I issued a heading of 260 for the base turn. I then noticed their ground speed was faster than I expected; so I issued the turn to final with an approach clearance. I let them fly approximately another 2 miles and noticed they were not turning or turning very slow which was going to take them across the localizer and into a higher MVA of 10900 ft. I then instructed Aircraft X to 'tighten up the turn' and issued a low altitude alert with a climb to 10900 ft. I observed them start a climb then I gave 'vector across the localizer' with a new heading of 020 and maintain 11000 ft. until established. Aircraft X landed without further incidentThe ZZZZZ arrival that Aircraft X was on has a bottom altitude of 10000 ft. but it also has a speed restriction of 210 knots. I didn't think twice about issuing 10000 ft. as Aircraft X neared the base turn because that is the bottom altitude of the STAR. I had done the same turn to final multiple times earlier in the shift without incident. Because I had issued the altitude as a descend and maintain the pilot did not fly the speed assigned on the arrival and I noticed too late. I was about 2.5 miles away from the localizer when I issued the [approach clearance] so I felt like it was plenty of time for them to join the localizer; but it would have been better for Aircraft X to be at a slower speed.