How do I approach my manager about a problematic co-worker, without making things worse for myself?

I'll try to keep this short and to the point. I work in a remote environment, as do my coworkers. There's 3 of us in my team: me, Jack, and Susan (fake names). Our responsibilities are primarily taking incoming calls. Jack is an alright employee. Susan is the equivalent of scratching a chalkboard.

Susan is often away from her computer. On average, she is missing for 2-3 hours of her shift each day, not including her lunch break. Given our primary responsibility of taking calls, this means that Jack and I have to take far more calls during these times. And when Jack is on break, and Susan should be working but is also away, I end up completely alone.

Susan also likes to skip out on work and just not show up. She doesn't inform the team or the manager when she does this. Normally, if she informed the manager that she'd be away, we would ask someone from our department to help cover the phones, but since the manager doesn't know, we end up short staffed on the phones.

As a result, I'm frequently feeling burnt out during and after work. I'm exhausted and during our busier periods, I struggle to get my secondary responsibilities completed in time due to the increased workload.

I've wanted to speak with Susan, but I don't see it helping my situation. She has a history of lying to me, so I'd expect to hear a lie (or worse, I feel that she would complain about me to HR or the manager). Instead, I've considered speaking to the manager. But since the manager hasn't taken any steps to resolve this, I'm concerned that such a conversation won't go over well.

What do I do here? As managers, what would you say if this was brought up to your attention? Am I in the wrong here for wanting to complain? Would my job be at risk considering I've been here for only around 2 years?