Does starting a family law equalization claim use up the time I'd otherwise have for a dependant support claim?

No — these are two separate legal claims on two separate clocks, and starting one doesn't eat into the deadline for the other. A surviving spouse's election to take an equalization payment of net family property under the Family Law Act must generally be made within six months of the death. A dependant support claim under Part V of the SLRA runs on its own six-month deadline, starting from the grant of the Certificate of Appointment of Estate Trustee (probate), not from the date of death. Filing one doesn't shorten, pause, or otherwise use up the time available for the other.

That said, the two claims can arise from the same family situation and raise overlapping facts, so it's worth thinking about them together rather than in isolation — a court can consider both in some circumstances, though there's no fixed formula for exactly how they interact. Because the two deadlines are triggered by different events and can land at different times, anyone weighing either claim should get legal advice promptly so neither window closes unnoticed.