I suggest politely asking them if you can train in. If you get a jerk-type answer, don't be surprised. I've found that meathead-types tend to disrespect women who want to use free weights.

You could also ask the gym to add equipment, since people are waiting to use certain things. I'd also recommend learning to use completely free weights - there's nothing you can do on a smith machine that you can't do without it, you just will need to use lighter weight. You can often also swap out cable machines with free weights to train the same muscle groups if all the benches are taken. This will also give your body a new challenge and could take your workouts to the next level.